CPUs and Motherboards: Monopolies Make for Easy Buying Decisions

Processors:

So, the last time I wrote a big Motherboard/CPU post, Bulldozer was in the offing and even those of us on Intel platforms were probably cherishing hopes that AMD would start competing in the enthusiast CPU space again.  As is so often the case, hope was simply the first step on the road to disappointment.  Bulldozer was disingenuously marketed (really AMD, 8 cores?) and hopelessly outclassed by an architecture that released months before it did.  Since then, AMD has abandoned the enthusiast market to focus on APU and (presumably) mobile development in order to cling to relevancy.

The silver lining here is that AMD's incompetence has made building a PC easier for everyone: just buy an Intel proc.  "But it's not that simple!" you cry.  Admittedly, AMD's APUs are a nice product for the niche they occupy, but most people building a PC want discrete graphics, or aren't doing anything beyond the capabilities of an Intel integrated GPU.  Intel CPUs are the right call in almost all cases. 

Anyway, after making AMD look bad without even really trying, Intel released Ivy Bridge, a Sandy Bridge die shrink that includes Tri-Gate transistors as well as support for PCI-E 3.0 and a few other new gizmos.  In terms of processor performance, Ivy Bridge isn't a big improvement over Sandy Bridge, so the recommendations haven't changed much:

Intel Pentium G620/Celeron G550 - ~$60.00:  For the builder on a budget, the Pentium/Celeron is a perfect compromise.  It isn't clocked as high as an i3 and lacks some features from the higher end Core line (any kind of overclockability, Turbo Boost, Hyper Threading, Quick Sync, etc.) but that doesn't mean it isn't still great value.  Don't let the price fool you, it'll keep up with most workloads, and won't hold your video card back when you start up Pong or whatever other newfangled nonsense you rapscallions are playing these days.

Intel Core i3-2100 (Sandy Bridge), Intel Core i3-3220 (Ivy Bridge) - ~$120.00:  Ivy Bridge Core i3s don't come in quite the same number of "flavors" as the Sandy Bridge versions (at least not yet) but there's something out there for basically everyone.  For basic usage in a run-of the mill gaming PC, the i3-2100 (or i3-2120, depending on pricing) or the i3-3220 are your go-to chips.

Intel Core i5-2310 (Sandy Bridge), Intel Core i5-3350P/i5-3330 (Ivy Bridge):  Not everyone needs an overclockable proc, but many people are still interested in quad-core CPUs.  More games and applications are starting to take advantage of higher core counts, so those desiring four cores at a more affordable (read, sub 200 dollar) price are advised to look at these procs.  The "P" designation indicates that a lack of onboard video, so keep that in mind.

Intel Core i5-2500K (Sandy Bridge), Intel Core i5-3570K (Ivy Bridge) - ~$220.00:  The 2500K is still fantastic and is usually priced around $220.00, but seems to go on sale fairly often and can drop to $200.00.  The i5-3570K is often slightly more expensive, but is almost indistinguishable from its predecessor, performance-wise.  As mentioned above, Ivy Bridge does enable PCI-E 3.0 and some other benefits, but depending on your usage and equipment, either proc can be the right choice.  The 2500K generally OCs a bit better, particularly on air.

There's really no reason for the vast majority of buyers to look at more than the 2500K/3570K can offer.  Hyper Threading is not a particularly significant addition given the workloads of most home users, and that's really all the extra Benjamin buys you.  Those of you with niche cases that aren't covered by the above recommendations are welcome to ask in the thread or PM me regarding what you might need.

Motherboards:

All the processors I'm willing to recommend are on LGA 1155, but there are multiple motherboard chipsets available for these CPUs, split between Cougar Point chipsets (introduced with Sandy Bridge) and Panther Point chipsets (introduced with Ivy Bridge).  H61 is the most budget-oriented of the Cougar Point chipsets, and would be most appropriate for a very low cost build utilizing a Celeron or Pentium CPU.  H67 is the next step up, and generally these boards have more complete feature-sets, but are not SLI/CFX capable and do not allow for overclocking.  P67 allows for overclocking and multiple video cards, but does not provide the ability to utilize the integrated GPU as well.  Z68 followed after and enabled use of the integrated GPU, along with some other processor features, and some boards on this chipset include PCI-E 3.0 compatibility when used with Ivy Bridge procs.  The most relevant new chipsets are Z77 and H77, which released with Ivy Bridge.  They are backwards compatible, though PCI-E 3.0 will not work with Sandy Bridge procs.  For full enthusiast-class systems, there's no good reason not to just go with a Z77 board, it does everything a P67 or Z68 board could do and more.  H77 is an excellent chipset for lower-end systems that don't need overclocking capability, but H67 and H61 are not necessarily significantly less capable, and may be better values depending on your processor choice and desired feature-set.

There are a few manufacturers I would consider to be most worth considering for your purchasing dollars:

ASUS – ASUS is probably my favorite motherboard manufacturer.  I'd go with ASUS if you’re looking for a board with fairly cutting edge tech, and useful extras like built-in Wi-Fi and/or Bluetooth.  They have a number of different product lines, including the Republic of Gamers motherboard line for really high-end builds.

Gigabyte – Gigabyte has a reputation for rock solid reliability, which anecdotally I can verify, as I own a few of their boards myself.  VRM quantity and quality over their range of boards is very much in line with ASUS offerings (if not better).  Gigabyte has generally solid layouts (with some odd choices at times) though their board lineup can be tough to navigate due to similar model numbers (like UD3 vs. UD3R vs. UD3H).  Gigabyte generally stays a bit more conservative than ASUS with fancy tech and gadgetry, though they have gone whole hog on including mSATA slots on their boards for cache drives.  Instead of stuff like onboard Wi-Fi, you generally get a larger and more comprehensive set of ports.

MSI – MSI is my least favorite of the “Big 3” motherboard manufacturers.  Much of this opinion is probably lingering prejudice related to their AM3 boards and some questionable decisions in some of their P67-based boards.  MSI has recently been pushing Thunderbolt onto some of their higher-end offerings.  Their current offerings are very competitive, and while I might prefer ASUS or Gigabyte myself, there’s really no good reason not to consider MSI at the moment.

ASRock – ASRock sprang out of ASUS spinning off a company specifically to make budget motherboards.  They’re generally considered a “budget” manufacturer, but their Sandy Bridge offerings were very strong, with good VRMs in their enthusiast level boards, and solid layouts.  Those same enthusiast offerings also set themselves apart with very aggressive pricing and solid accessory sets.  Their Ivy Bridge offerings have continued that trend.  The documentation and BIOS/UEFI interfaces aren’t as polished as their higher-end competitors, but if you can deal with that, you can often get a really nice deal.

Beyond manufacturer, you should take into account the following criteria (along with price, naturally) when choosing a board:

Form Factor:  Be aware of the motherboard form factor, it’s crucial in ensuring compatibility with your case.

SLI/Crossfire capability:  This generally comes at a price premium, but if you’re genuinely going to take advantage of the capability, it’s worth the money.  If you are certain that you want a single card system, and have no plans to either add a second card in the future, or have 2 cards to start with, do not pay the premium.  And be realistic with yourself about the possibility of upgrading with a second card as well.  However, if you have the budget, and do think it’s a possibility, spend the money, you won’t regret it.

The basic requirement for SLI is 2 physical PCI-E x16 slots, which run at least at x8/x8 when both are populated.  Crossfire can run on 2 physical x16 slots that run at x16 and x4, but performance is compromised and I wouldn’t recommend it, at least x8/x8 is your best bet.  Higher end motherboards (or motherboards on higher-end sockets) may support multiple x16 slots running at a full x16.  For 2-way SLI/Crossfire, x8/x8 on PCI-E 2.0 is enough bandwidth to avoid throttling all but the highest-end of last-gen cards (and even then the performance loss is minimal).  I'd recommend a board and processor that are fully compatible with PCI-E 3.0 if you want to run multiple high-end cards from the current generation of GPUs.

VRMs:  The VRM system in your motherboard is the system that takes power from the PSU and converts it to the correct voltage to be utilized by the CPU and GPU.  If you see stuff like “12+2 power phases” being tossed about, that’s referring to the VRM system of your motherboard.  Basically the VRMs are small transformers that convert the +12V from your PSU into the correct voltages to run your stuff.  Phases refer to the number of transformers, the more you have, the lower the individual load on each transformer, which means a more stable, long-lasting board, especially when overclocking.  If you’re pushing things, poor quality/too few VRMs can mean catastrophic damage to the motherboard, and perhaps other parts as well.  For Sandy Bridge/Ivy Bridge, I would consider 6+2 to be adequate for reasonable overclocking, with 8+2 desired and anything above that being gravy.

Physical layout:  This is pretty important, especially in this age of double-wide GPUs and SLI/Crossfire setups.  For SLI/Crossfire motherboards, you want at least an additional expansion slot’s worth of space between PCI-E x16 slots in order to accommodate 2-slot GPU coolers.  For motherboards supporting only 2 GPUs, I’d recommend looking for 2 slots worth of space between, to give the top card some breathing room.  SATA ports should be either of the 90 degree variety, or placed to ensure they won’t be covered by longer graphics cards.  Front panel, audio and USB headers should be located along the edge of the board, easily accessible and away from any potential conflict with expansion cards.  Keep an eye on stuff like CPU socket positioning relative to DIMM slots, and the size and positioning of heatsinks on the motherboard.  Manufacturers are generally very good about avoiding those conflicts, but depending on heatsink size and layout you can sometimes have trouble mounting aftermarket CPU cooling.

BIOS/UEFI:  If you're looking at an overclocked system, you'll want a nice, full-featured BIOS/UEFI.  Some budget boards (even from otherwise high-end manufacturers) have taken to removing deeper, more complex customization options, and some manufacturers have very poorly put together interfaces, with nonsensical descriptions and confusing layouts.  Obviously, you'd like to avoid those if possible, so make sure to take a look at some reviews to see if you can't get an idea of what you'll be looking at.

Features and Documentation:  This is more nebulous, as it’s entirely up to your own discretion.  Each builder has different needs in terms of feature-set (quantity/type of ports, additional bells and whistles like Bluetooth, etc.).  Certain boards will come with automatic or software assisted overclocking options that other boards lack.  Do your research here, and choose the board that includes everything you need/want.  Similarly, some builders will need and/or want clear, comprehensive documentation of board features and installation, while others may be comfortable without it.

As for individual recommendations, I'll keep it fairly simple.  For basic builds (using Pentium/Celeron chips) go with the ASRock H77M.  For mid-range builds (using a Core i3 or non-K Core i5) go with the Intel DH77EB.  For high end builds (using Core i5 2500K or 3570K) go with the Gigabyte Z77X-UD3H.  If you need something fancier, or more esoteric, feel free to PM me or ask in the thread.

Let's Talk About Sandy Bridge E

Now, the last time I did something like this, it was regarding AMD's Bulldozer platform, which is thoroughly (and likely un-redeemably) mediocre. At the end I concluded that there was little reason to buy into it if you were looking for a new PC, and that it's primary selling point (loads of cores at bargain basement prices) was more solidly addressed by the Phenom II X6 processors that AMD already has. Sandy Bridge E isn't the same story (indeed, far from it) but the end result is the same: you shouldn't buy into this platform.

Sandy Bridge E is a benchmark crushing series of processors. You're talking about 6 real cores, with HT and serious overclocking potential. The die is titanic by comparison to a standard Sandy Bridge die, and it doesn't even include an IGPU! In every performance metric, Sandy Bridge E outperforms its predecessor, not to mention the absolute hash it makes of AMD's offerings.

Unfortunately, Sandy Bridge E's performance is matched, then exceeded, by the price of the platform as a whole. The cheapest Sandy Bridge E processor is as much or more expensive than the top of the standard SB heap, and if you're buying into Sandy Bridge E for a glorified 2700K, you're doing it entirely wrong. Then you have to consider the price of a solid motherboard, the cheapest of which will likely start in the $200 range. When you consider the fact that the performance offered by a 2600K/2700K was already well in excess of what is necessary for gaming and general computing usage, it becomes incredibly difficult to justify Sandy Bridge E as a computing platform for the general consumer.

You would want Sandy Bridge E if you are, say, starting your own space program, or plotting to take over the world. You might use it as the centerpiece of a device designed to use mathematical calculations to warp the very fabric of reality. I'm not entirely convinced it couldn't be used to resurrect the dead.

All of that doesn't mean that super-villains are the only people who could use the kind of horsepower that you get out of a Sandy Bridge E based PC. Professionals with video editing, 3D rendering, and/or CAD needs will find this kind of number-crunching ability compelling, as will those involved in high-end computing/distributed computing projects, like Folding@Home. Still, those with the need for that much processing power are decidedly in the minority, and those outside that minority who buy into the platform are undoubtedly enthusiasts with deep wallets and misplaced priorities. Normal people with reasonable budgets and no deep-seated need to compensate for something will be perfectly happy on the LGA1155 platform.

Bulldozer: The more things change, the more they stay the same.

It's been a good long while (my apologies) but we recently had a major new processor launch (though not a chipset launch, AM3+ boards of varying feature sets and expense levels have been available from most vendors for months now) so I thought I'd toss out some thoughts.

To be brief, so far Bulldozer really doesn't seem to be worth your time or money, especially for those of you poised to purchase something in the 2500K area.

To give it the long treatment, I'll start by saying that I wasn't too keen on Bulldozer.  The 8-core approach (at least for the "high-end" SKUs), while certainly ideal for those of us who really love heavily threaded applications, really doesn't do much for the vast majority of us who are building gaming PCs.  Without per core performance closer to that of Intel's Sandy Bridge chips (and many benchmarks indicate that, on a per core basis, Bulldozer fails to significantly outperform AMD's own Phenom II lineup) the reality is that Bulldozer wasn't going to be a compelling choice over Intel's 1155 lineup without a serious price advantage.

Unfortunately, that price advantage has failed to materialize.  For users with heavily threaded applications (which does not include the vast, vast majority of games, or most standard consumer productivity apps) the 8150 might represent a relatively inexpensive way to get 8 real cores, but a Phenom II X6 will likely provide you with the majority of that performance at lesser cost.

Bulldozer does emerge victorious in instances of really heavily threaded workloads, but most users really don't experience those kind of workloads with enough regularity to make it worthwhile, especially when Sandy Bridge offers such compelling per-core performance advantages.  Newer iterations of AM3+ based CPUs may offer the kind of competition we'd like to see from AMD, but for now Bulldozer is a product destined for niche users and those who absolutely refuse to be parted from their AMD products.

A Visual Guide to PC Components Pt. 1: CPUs and Motherboards

Though the thread tends to attract those who are already computer-savvy enough to know what the inside of a PC looks like, not everyone who can competently wield a computer knows what individual components go into building one.  The following is a visual guide to some salient PC components, for the edification of potential PC builders.  The important thing isn't the specific model of the parts you'll see below, but the general understanding of what individual components look like and where they go in the system.  Apologies in advance for any cruddy photos, I'm no photographer and I'm working with a relatively ancient point-and-shoot.

CPUs/Processors:

AMD Processor (Athlon II X2 250)

AMD Processors generally have an entirely flat heat-spreader that covers most of the silicon wafer.  You can see the designation of the processor there on top (AMD Athlon II) along with the model number.  You can't see this, but on the opposite side of the CPU are the pins, which slot into the socket on the motherboard, where they touch the contacts inside the socket.

Intel Processor (Intel Core2Duo E4500)

Though this is an older model CPU from Intel, they've been using roughly the same wafer size and heat-spreader design for at least the past 3 processor generations, and it seems unlikely to change any time soon.  Once again, the model number and CPU type are shown on top.  Unlike the AMD CPU, the heat-spreader has a couple "steps".  Modern Intel CPUs reverse the traditional CPU/Motherboard interaction: the contacts are on the CPU, while the pins are built into the motherboard socket.


Motherboards:

AMD Micro-ATX Motherboard (ASRock 880G LE AM3)

The above is an AMD AM3 Socket motherboard (which will eventually hold the AMD Athlon II X2 processor you saw earlier).  The motherboard is based on the Micro-ATX form factor, so it's smaller than a standard motherboard, and comes with a maximum of 4 expansion card slots.  I've indicated some points of interest on the motherboard for you to take a look at.

1. 4-Pin CPU Power:  Power from the PSU cable that plugs in here is directed to the CPU.  Higher end motherboards will have 8-Pin power connectors, in order to provide more power to the CPU, which assists in overclocking, or in running higher powered CPUs.
2. VRM system:  Here you can see the chokes and MOSFETs that make up the VRM system (the system that takes 12V power and converts it to lower voltages) for the CPU.  If you count the chokes, there are 4, pointing to 3+1 power phases, which isn't great, but it's for a media server, so I don't need much.
3. CPU Socket:  This is the socket for an AM3 CPU.  The socket arm swings up, you orient the CPU correctly, and all the pins drop into the little holes in the socket, then you swing the arm back down.  The plastic bracket around it is for CPU coolers.
4. DIMM Slots:  This is where your RAM goes.  You pop open the little arms on the sides, then seat the RAM.  You'll know it's fully in when the arms click in and secure it on the sides.
5. 24-Pin Motherboard Power:  Like the CPU Power plug, you'll run a cable from your PSU to this.  In older PCs (and some modern low power systems) the only thing necessary to run the system was this connector, which also delivers some power to the CPU.  Aside from that it delivers power to the rest of the motherboard components, and any expansion cards that are power strictly by the slot they're placed in.
6. SATA Ports:  Here we have 3 SATA II data ports.  Drives (Optical Drives, Hard drives, Solid State Drives) are attached to these ports via a SATA cable.  Depending on the motherboard, you might see ports oriented as the are here, perpendicular to the PCB (Printed Circuit Board) or oriented parallel to the PCB.
7. PCI-E x1 Slot:  This is a PCI Express x1 slot.  The x1 indicates available bandwidth on the slot.  x1 slots are used for basic expansion cards, like Network Interface Cards (wired or wireless) and sound cards.
8. PCI-E x16 Slot:  PCI Express x16 slots are physically larger than lower bandwidth slots and are mostly used for the addition of discrete graphics cards.  They are compatible with any lower-requirement expansion card (you can use a x16 slot to run an expansion card that needs a x1 slot).
9. PCI Slot:  PCI slots are probably the oldest design still incorporated into modern motherboards.  Regular PCI is slower than the PCI-Express interface and is largely useful for legacy expansion cards that you aren't willing to part with (like if you have a really old modem or NIC that you'd like to keep using).

Intel ATX Motherboard (ASUS P8P67 Pro)

So here we have an Intel motherboard based on the ATX standard.  Full ATX motherboards have a maximum of 7 expansion card slots.  Otherwise the functions on this board are largely identical to the AMD board above.  This board does have double the available DIMM slots for RAM, 2 more SATA ports with all the SATA ports oriented parallel to the PCB, and 8-Pin instead of 4-Pin CPU power.  The VRM system is also located under passive heatsinks around the CPU socket.  You'll also note the cover over the CPU socket.  Because the CPU socket for Intel motherboards contains pins, rather than contacts, a cover is necessary to protect them while not in use.

And with that, we come to the end of our regularly scheduled programming.  We've familiarized ourselves with CPU and Motherboard design, expect to see a visual guide to the PSU soon.

Motherboards & CPUs: The Electrified Heart of your PC

08-18-2012: A lot of this information is still useful in a general capacity, but much of it is somewhat outdated.  You can find a more recent version of the post here.

Motherboards and CPUs are system defining components, so be prepared to spend some time and effort on deciding the right combination for your purposes.  They dictate your upgrade paths, your overclocking possibilities, they contribute hugely to the performance of your system, and they're central to a number of other decisions you'll make as you build a PC.

Motherboards

Choosing the right motherboard can help you build a well-balanced, upgradeable system with features aplenty.  The wrong motherboard can lead to copious RMAs and wasted time and effort.  Below you'll find information and recommendations to take some of the guesswork out of choosing the right board for you.

So what stuff matters in a motherboard?

• Form Factor:  Be aware of the motherboard form factor, you don't want to end up with a motherboard that won't fit in your case.

• SLI/Crossfire Capability:  This generally comes at a price premium, but if multiple GPUs are in your future (or present) it's worth the money.  However, if you are definitely only going single card, and don't envision yourself ever using multiple GPUs, don't pay the premium.  The basic requirement for SLI is 2 physical PCI-E x16 slots, which run at least at x8/x8 when both are populated.  Crossfire can run with a card in a x4 lane, but performance is compromised and I wouldn't recommend that, x8/x8 as a minimum is your best bet.  Higher end motherboards (or motherboards on higher end sockets) might support multiple x16 slots running at the full x16.  Currently that's limited to higher end AM3/AM3+ boards, X58 boards, and P55/P67/Z68 boards with the NF200 chip.  For 2-way SLI/Crossfire, x8/x8 is enough bandwidth to avoid bottlenecking all but the highest of high-end cards, and even then performance loss is relatively miniscule.

• VRMs:  The VRM system in your motherboard is a series of small transistors that function as transformers, taking the +12V power from your PSU and sending it to the CPU, GPU and motherboard components in the correct voltages for those parts.  When you see things like "12+2 power phases" being tossed about, they're referring to the number of VRM transformers (in this case, 12 for CPU power and 2 for GPU power).  More power phases means lower individual loads on each transformer, which makes for a more stable experience, especially when overclocking.  Fewer VRMs, or VRMs of inferior quality, can mean catastrophic damage to the motherboard and potentially other components if you push things too far. 

• Physical Layout:  The advent of all double slot GPUs all the time has made the layout of the board, in particular the PCI-E slots, of even greater importance than before.  For SLI/Crossfire capable motherboards, you want at least 1 additional expansion slot's worth of space between PCI-E x16 slots to accommodate 2-slot coolers.  For motherboards supporting only 2 GPUs, I'd recommend looking for 2 slot's worth of space, to give the top card room to breath.  SATA ports should either be of the 90 degree variety (so parallel to the PCB) or placed to ensure they won't be covered by longer graphics cards.  Front panel, audio, and USB headers should located on the edge of the board, away from potential conflict with expansion cards.  Along the bottom edge is usually best.  Keep an eye on CPU socket positioning relative to DIMM slots and motherboard heatsinks.  It's tough to avoid DIMM slot conflicts, but most motherboard manufacturers are very good about making certain their motherboard heatsinks don't interfere with aftermarket CPU coolers.

• Features:  This is more nebulous, because what constitutes an acceptable set of features is entirely up to the builder's discretion.  Make sure you're buying a board that has all the ports and additional bells and whistles that you desire.  Some boards come with automatic hardware/software assisted overclocking options, for example.  Do your research here, and choose a board that gives you what you want.

What motherboard brands are worth checking out?

• ASUS - ASUS is currently my favorite motherboard manufacturer.  They usually have some of, if not the, best VRM setups around, and their boards are usually feature-packed with good layouts.  They tend to keep their board lineup relatively simple, which does help prevent confusion.

• Gigabyte - Gigabyte has a reputation for reliability, which I can anecdotally confirm based on my Gigabyte X58 board.  Their high end and mid-range boards usually come with solid VRMs, though their lower end offerings can be stingy in that area.  Gigabyte generally has solid layouts (with a few questionable calls, like on front panel audio header placement).  Their board lineup can be a maze of secondary designations and extremely similar model numbers (UD3 vs. UD3R for example), and they have not yet moved to UEFI based BIOS.  Many of their Z68 boards also don't support the GPU virtualization technology that makes the switchable graphics for that platform possible  (this shortcoming has been largely addressed by a new wave of Z68XP boards with the Virtu chip onboard).

• MSI - MSI is my least favorite of the "Big 3" motherboard makers.  Their AM3 lineup was notorious for poor VRMs, even the boards that had sufficient power phases endured engineering/manufacturing defects that could cause VRMs to die in a fire.  Literally.  MSI's layouts for Sandy Bridge have been the worst of the Big 3, with front panel headers and vertical SATA ports placed directly under areas where a second GPU would rest.  In general, their motherboards don't seem as well built or as well designed as competitor's boards in the same price range.  With the TDP and power reqs of Sandy Bridge being so low, and the quality of the VRMs being (hopefully) fairly high, most 115 MSI motherboards aren't likely to be genuine liabilities, but generally I think your money is better spent elsewhere.

• ASRock - ASRock sprang out of ASUS spinning off a company specifically to target budget-conscious consumers, and as such ASRock is often (though perhaps unfairly) lumped in with companies like Biostar.  Their 1155 offerings contradict that impression, though, with generous VRMs, good layouts and accessory bundles, not to mention their aggressive pricing.[/LIST]

As you'll find in the Processors section, my current opinion is that Intel's 1155 socket is the best option available for all but the most restricted of budgets. 1155 boards come in a few flavors, but the ones suitable for overclocking and SLI/Crossfire usage are either P67 based, or Z68 based. Z68 includes a few additional features on top of those included in P67 boards. Z68 allows for SSD caching, which is useful for those who have a small SSD (usually around 30ish GB) that they'd like to use as a cache. This will improve disk performance and general system responsiveness, though not as much as having an SSD as your boot drive will, so it's of utility only for those with an SSD that is too small to use as a boot drive. Z68 also includes support for using the built-in GPU of Sandy Bridge processors to accelerate video encoding/transcoding. Unfortunately, while there are significant speed gains available using this process, very few transcoding/encoding applications support this at the moment. Z68 boards with the Virtu chip also support using the integrated GPU during low load situations (at desktop, for basic video playback, etc.) in order to reduce power consumption. All in all, Z68 is of relatively little utility, especially if you don't have an SSD or don't need to use one for cache. P67 generally has a price advantage, and the feature sets are so similar that I don't see much reason to pay more. Just for the sake of completeness, though, Z68 boards are included with the P67 recommendations below.

P67:
$150 - ASRock P67 Extreme4 Gen3
$180 - ASUS P8P67 Pro
$190 - Gigabyte P67 UD4

Z68:
$175 - ASRock Z68 Extreme4
$190 - ASUS P8Z68-V Gen3
$180 - Gigabyte Z68XP-UD3P

Options on the low and high end:  For those building with non-K CPUs, fewer VRMs and/or less effective VRM cooling is less of an issue, as there is no overclocking to stress them beyond normal levels.  With that in mind, a solid H67/H61 board is a good bet.  For those looking for very high-end boards (perhaps with support for more than 2 GPUs, or multiple x16 lanes) please ask in the thread.  There are several different offerings, and your particular feature needs and case selection will be important in determining what board is best for you.

Processors

Compared to motherboards, where layout, build quality and feature-set are the primary concerns, CPUs are a numbers game.  Synthetic and real-world benchmarks will tell the story of a proc's prowess, so benchmarks and reviews are your independent research pals.  Right now the best processors at reasonable budget levels are Intel's Sandy Bridge processors.  They are faster, clock for clock, than previous Intel and current AMD offerings, and are relatively budget friendly.

The current recommendations:

Intel Core i3-2120 - $127.00: Suitable for budget levels ~$600.  This is a really solid dual core (with HT) that will hold up its end in all arenas.  It's not going to match a real quad-core in heavily threaded apps, but it's not going to be holding your GPU back.

Intel Core i5-2400 - $190.00: Suitable for budget levels ~$800.  The 2400 isn't vastly cheaper than the 2500K, but you can run a cheaper H67 board with it and not lament the loss of overclocking potential, so that helps keep costs down.  Despite its overclocking limitations, it's a great quad-core.

Intel Core i5-2500K - $230.00: Suitable for budget levels ~$1000 and up.  The 2500K doesn't give you Hyper Threading or do your homework, but that's just about the only stuff it won't do.  It's hugely powerful, hugely overclockable, and at $220.00, remarkably affordable.

Options on the low and high end: For really low budget options, I recommend asking in the thread. On the high end, there are the i7-2600/2600K, or the i7-2700/2700K (essentially a 2600/2600K with slightly higher stock clocks). The basic differences between the 2500K and the 2600K are a marginal stock clockspeed and cache advantage on the 2600K's part, and the 2600K has Hyper-Threading. If you do a lot of heavily threaded workloads, like high-end photo/movie editing or graphic design, the 2600K might justify it's $100 price premium over the 2500K. But if you're just an amateur Photoshop enthusiast while you aren't gaming, stick with the 2500K, it's more than enough CPU to handle the vast majority of tasks.

The other option on the high end is to switch Intel's ridiculously overpowered and overpriced LGA2011 platform and use a Sandy Bridge E processor. As I said in this blog post, I don't see any compelling reason for the majority of users to want the kind of horsepower (and expense) that goes along with Sandy Bridge E, but if you're a nutjob for whom price is no object, or a professional who could genuinely use that much horsepower, it is an option.