Intel hits back with a great budget chip.
As you've probably already read just now, AMD's latest chip just edged over the 4GHz mark. When Intel sent us its quad we didn't have such a high expectation - but we proved ourselves wrong! This has two more cores than the Phenom X2 and a lower starting clockspeed, but who comes out on top?
Built on the 45nm process that Intel has now got worked down to a fine art, there are 456 million transistors packed into a die of only 164mm2. It's based around the same Yorkfield die as all recent Core 2 Quads, but has a cut-down amount of L2 cache at only 1MB per core. The 95W TDP is very similar to Intel's Quads in this series, and the 8x locked multiplier means that you don't have too much wiggle room on that side. Unlike the Q8200 this chip has Virtualisation tech enabled, as well as all the usual 64-bit features. This runs on a 333MHz FSB for an effective speed of 2.66GHz. On paper it's reminiscent of the incredibly popular Q6600, and pricewise it's perfectly situated at $260.
Unlike AMD's native quadcore design, the Core 2 Quad is essentially two Core 2 Duo dies sticky taped together to form something that is very similar to a native quad. This means that Intel can get very high yields on their chips, and are very flexible when it comes to mass-producing them. Unfortunately this CPU isn't quite as easy to work with as the AMD; but in no way does that mean it's a huge challenge. Throwing it into our P45-based test-rig with a trusty TRUE heatsink on top, we got around to benching and what we found was very interesting.
Compared to AMD's chip at stock speeds, the Intel chip loses out across every test except for multithreaded ones. The slower clock speed and memory controller located in the northbridge (as opposed to on the die like AMD) means that the latencies here in the tech keep the quad just behind the competition. When we dialled in our second OC level we got much the same story as at stock, tailing just behind without quite beating the AMD silicon. The third level is where we saw the Q8400 catch up to and actually beat the AMD processor in some singlethreaded benchmarks, which was very impressive.
Of course the extra two cores available to the Quad completely decimate the dualcore in multithreaded apps, wiping the other CPU over the floor. The important question is though; can it beat the 4GHz overclock?
We sat down and deftly raised the FSB to 500MHz, which gave us an incredibly easy 4GHz overclock at only 1.4V Vcore. This is something that you can almost literally dial in and be happy with assuming you have an aftermarket cooler, and is a great display of the tweaking that Intel has put into their R0 stepping silicon. Not content with such an easy leap, we kept pushing the FSB up until we topped out at a maximum of 518MHz at 1.4625V - giving us a final maximum speed of 4140Mhz.
For a quadcore to best the overclocking capacity of a dualcore is impressive enough; for it to do it on an identical heatsink to a CPU with lower TDP is even more so. The Q8400 might not have a huge amount of cache compared to other chips, but in the race between the two in this magazine we're going to call it on the blue team's side this time - for only $115 more you get two extra cores and more overclocking headroom; what's not to like?
Issue: 107 | December, 2009