At the stock 2.66GHz speed, the D0 draws 15W less power than the C0. When we overclocked it to 3.9GHz (20 x 195MHz) using a core Voltage of 1.35V, the difference in power draw increased to 55W in favour of the D0. This was looking very promising, and we fully expected that the 920 D0 would go even faster but things didn’t work out that way.
Power Draw Results
Power draw in Watts
We could overclock to 4GHz (20 x 200MHz) on 1.35V but the system crashed repeatedly while encoding files in DivX 7. When we fed the 920 D0 1.40V and bumped the speed further to 4.1GHz (20 x 205MHz), it became even more flaky.
The power draw of the D0 at these increased speeds was still lower than the overclocked C0 but the performance simply wasn’t there. We can't comment on the performance of Core i7 950 as we have yet to see one but we suspect it will follow in the footsteps of the new Core i7 920 and will be slightly slower than the new 975 Extreme.
You have to ask yourself why Intel brought out the 975 Extreme and the only logical answer is that it doesn’t want to be seen as a company that rests on its laurels. Instead, it constantly strives to make progress and keep ahead of that pesky AMD.
No matter what the reason, the D0 Stepping is a success. But let’s face it, you’re not going to spend £800 on a new desktop processor and you probably don’t know anyone who will. You should, however, cough up the necessary for a new Core i7 920 for which the D0 Stepping is the key to a world of gaming goodness. It overclocks superbly well and the reduced power draw is quite remarkable.
Intel has given the Core i7 family a buff and wax with the new D0 Stepping, and the reduction in power draw is deeply impressive. ®
More CPU Reviews...
Intel Xeon W5580
AMD Phenom II Socket AM3
Intel 'Nehalem' Xeon 5500
Intel Core i7 'Nehalem'
Intel Core i7 975 Extreme
less power = less heat = less cooling required
This means less noise, greater stability and potentially increased headroom for further overclocking.
power draw? who cares?
I am sure that sounds very mean spirited and anti-earth, but who is reading these evaluations? Dell? HP? Nooooo, people who are going to build a few machines at best and likely only 1, this year. They want maximum smoke ... as in speed.
Ok, I know that is is all pc to talk about crunch per watt, so fine.
Damn, no bitey ;-)
To be fair, if you are running [good] water cooling then it will probably go usefullyt further than a 920 - but even if I had a hypothetical £2k to wang on a rig, I still think that, say, three or four high end GPUs SLI/Crossfired up would make more of a difference than the Extreme. especially once the OpenCL-esque code starts appearing in a couple of years for GPGPU tasking - such as on Snow Leper, er, Leopard, etc.
That said, if I had £3k to spend...well, you're then in the position to start being a badge snob, and I'm always a sucker for that if I can when it comes to tech kit....
[PS: Should I come into £3k, I'll get your psychologists number...]
the scaling is completely wrong given how close the chips benchmark.
> Are you seriously suggesting that a couple of extra hundred stable megahertz - at best, from
> what I have seen - are worth the £500 extra for an Extreme processor?
Steven, nowhere did I suggest that it was actually WORTH the money. My only comment was that there IS a minor difference between the 920 and the 975 that wasn't mentioned. As to why I bought one ... well, I'll ask my psychologist about that.
(Actually I'm convinced that with the watercooling I'm employing and some combination multiplier and other overclocking tweaks then I can far exceed the possibilities of the 920 with the 975 but it's a bit of a gamble and it's distinctly possible I'll fail.)