Intel's Baffling New Broadwell CPUs

Intel has finally, belatedly, possibly even reluctantly wheeled out its latest 14nm Broadwell CPU architecture in desktop processor trim (we've seen it before as a mobile chip). And it's all a bit baffling. The new chips are not really direct replacements for Intel's existing Core i5 and Core i7 gaming favourites. They're not really faster, except when they occasionally are. And they set new standards for integrated graphics but still make absolutely no sense for gaming. In short, you needn't rush out and buy one.

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Jump to the bottom for the TL;DR

The backdrop to all this is Intel's 14 nanometre chip production tech. 14nm is, of course, the notional size of the tiny transistor gates inside the chips. Or something like that. The details probably don't matter. It's just bloody small and a shrink from the 22nm silicon that Intel uses for its existing Haswell processors, like the Core i5 4690K.

According to Intel's master plan, die shrinks like this come with only minor changes to the circuitry, the emphasis being on smaller transistors not the architectural design, though Intel hasn't always stuck rigidly to that. In this case, the CPU bits haven't changed much, but there's some pretty major new graphics goodness. Yes, like all other mainstream Intel CPUs, these things bave integrated graphics which you're not gong to use. More on that in a second.

First, the basics. Intel is pitching Broadwell as its 5th generation Core processor. At launch there are two relevant new chips, the Core i7-5775C and the Core i5-5675C. Yes, 'C' at the end, not 'K'. These two chips are unlocked for easy overclocking like the old K series CPUs, but they're relatively low power at 65W a pop (versus 80-odd for existing Intel CPUs aimed at gamers) and not terribly high clocked.

The 5775C is nominally 3.3GHz, with a 3.7GHz 'Turbo' mode, while the 5675C is 3.1GHz and 3.6GHz Turbo. Lest ye forget, the older Core i7-4790K Turbos up to fully 4.4GHz. Oh, and we're talking quad-core yet again and the usual Core i5 versus Core i7 distinction that sees the 7 get Hyperthreading, but not the 5.

Yep, it's still four bleedin' cores

Intel has also launched some Broadwells with 'R' suffixes, but these are BGA-packaged CPUs and thus soldered permanently to motherboards and not really in our collective wheelhouse. They're the sort of chips you'll find in pre-built small-form factor boxes, that kind of thing.

Price-wise, the two newbies slot in at similar but slightly higher prices to the existing 4690K and 4790K range toppers, as far as I can see, and thus from roughly £200 / $250 for the cheaper i5-5675C.

So, that's significantly lower clocks, the same core and thread counts for a bit more money and that weird new 'C' suffix. Oh, and the new chips drop into the LGA1150 socket and will be compatible with existing motherboards with 9 Series chipsets like the Z97 and H97, though you should check with your board maker regards BIOS support.

Like I said at the top, all fairly baffling. The explanation, as far as I can fathom, is that the 14nm delay has relegated these Broadwell chips to stopgap status before the real excitement happens later this year with the new Skylake generation and its fancy new chipset and added PCI Express connectivity.

If there is an aspect of Broadwell that's truly interesting, it's the graphics. Both the new chips get the highest performing version of Intel's new integrated graphics, codenamed Crystal Well and sold as Intel Iris Pro 6200. That means 48 Execution Units (up from 40 and each one tweaked for more performance) and 128MB of eDRAM embedded memory.

That memory is in a separate chip in the CPU package. It's mainly for graphics, but can also be used as level 4 cache memory to help prop up the CPU cores.

As for performance, I'm on the hoof in Europe currently so haven't had a hands on just yet. Early numbers from the usual suspects including Anandtech make for intriguing reading, but only if you are a CPU geek. Just occasionally, the eDRAM seems to boost CPU performance a little beyond expectation. Twist my arm and I'll admit that the positive impact on minimum frame rates in games looks borderline worthwhile, but only if you were already dead set on upgrading your CPU.

As for the performance of the integrated graphics itself, it's a tale of two halves. On the one hand it's clearly the fastest integrated graphics yet. But it's still marginal at best for actual gaming. You're looking at 40 to 50 frames per second in demanding games at middling to high details. If that sounds OK, the resolution in question is 1,280 by 720 (AKA 720p). Even 1080p at middling detail will often make for chuggy gaming.

Slightly better minimum frame rates in Mordor. That's all I got...or rather all you'll get

On a budget chip, that might be interesting. But these are pretty pricey processors, starting at roughly £200 / $250, so it would be madness not to run them with a proper graphics card.

So, there it is. I hate to grumble yet again about a new Intel CPU, especially when Intel is battling with the very laws of physics to bring us its 14nm silicon technology. But these new chips really are of almost zero interest to gamers and enthusiasts, the only possible exception being if they turn out to be overclocking monsters. The jury on that is out.

Instead, they exist in order that Intel can start to sell more 14nm product. They make sense from a business perspective, no doubt. The benefit to us punters of a desktop persuasion is far less clear. Once again, then, Skylake later this year remains the great hope for some interesting mainstream CPUs from Intel. If that turns out to be dreary, I will do a Paddy Ashdown and start eating hats. Or at least proffering ill-advised ultimatums about edible headgear.

Still, at least none of us need rush out and buy a new Broadwell CPU.

TL;DR
Intel has launched two new chips for existing LGA1150 9 Series motherboards, the Core i7-5775C and Core i5-5675C. They're built using fancy new 14nm transistors. They have the fastest ever integrated graphics of any CPU. But the integrated graphics still makes no sense for serious gaming. And CPU performance is mostly unexciting compared with existing Intel processors.