Intel’s Core i7-975 & 950: Preparing for Lynnfield
by Anand Lal Shimpi on June 3, 2009 12:00 AM EST- Posted in
- CPUs
The Fastest Processor for Single Threaded Tasks
In the past we’ve had to make concessions for single-threaded application performance on modern day quad-core processors. For example, $266 will buy you two 3.33GHz cores or four 2.83GHz cores from Intel. I generally recommend going the quad-core option but there’s no getting around the fact that you do give up some performance when an application can’t take advantage of more than two threads.
With the Core i7 Extreme 975 the CPU can run at up to 3.60GHz when only one core is active (3.46GHz if more than one core is active). In my testing I found that the CPU almost always ran at its maximum turbo frequencies.
The graph below shows single-threaded performance in Cinebench R10. Note that while the Core 2 Duo E8600 (3.33GHz) was the top performer in this test for quite some time, the Core i7’s Turbo Mode has ensured that it’s no longer true.
The fastest single-threaded processors are now Intel's quad-core, eight-thread Core i7s
The biggest issue I see with the i7’s Turbo Mode today is that you only get one speed bin improvement (+133MHz) if 2 or more cores are active. The biggest boost (+266MHz) only comes when only a single core is active. Perhaps we’ll have to wait for Lynnfield for that.
The Test
| Motherboard: | Intel DX58SO (Intel X58) Intel DX48BT2 (Intel X48) MSI DKA790GX Platinum (AMD 790GX) Gigabyte GA-MA790GP-DS4H (AMD 790GX) Gigabyte GA-MA790FX-UD5P (AMD 790FX) |
| Chipset: | Intel X48 Intel X58 AMD 790GX AMD 790FX |
| Chipset Drivers: | Intel 9.1.1.1010 (Intel) AMD Catalyst 8.12 |
| Hard Disk: | Intel X25-M SSD (80GB) |
| Memory: | G.Skill DDR2-800 2 x 2GB (4-4-4-12) G.Skill DDR2-1066 2 x 2GB (5-5-5-15) Qimonda DDR3-1066 4 x 1GB (7-7-7-20) Corsair DDR3-1333 4 x 1GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 280 |
| Video Drivers: | NVIDIA ForceWare 180.43 (Vista64) NVIDIA ForceWare 178.24 (Vista32) |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows Vista Ultimate 32-bit (for SYSMark) Windows Vista Ultimate 64-bit |
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silver250 - Friday, June 5, 2009 - link
Maybe I missed it but last time I saw a review with the Phenom II CPU's they ran better with DDR3, all the boards for AMD listed are only DDR2 boards.So whats the deal? Or did I just miss a reason somewhere in other reviews?
Tunnah - Thursday, June 4, 2009 - link
would it be possible at all to get the power usage stats of the overclocked version ? A while ago I was reading an article (not sure if here or elsewhere) and it gave the power usage per overclock step and was a great way of working out where to find the balance of power usage vs overclocking amount. Also I'd love to see the power this beast sucks up at 4.6ghz hatygrus - Thursday, June 4, 2009 - link
Are you able to measure the CPU clock freq while running the benchmarks to see the affect of the Turbo mode. Labelling as 3.2GHz when it could actually be 3.46GHz.Can we also see results with the Intel Turbo On & Off ?
Does Intel use core activity to determine Turbo limits or does the on-die temperature sensor allow using higher speeds at any time ?
Intel claimed a bit of both, but it seems very pre-set (1core max, 2core max, 4core max). Can it be overridden ?
How hot can the case temp be before the CPU is prevented from using higher speeds ?
How much activity on other cores will prevent the fastest setting of single core task ?
Hrel - Wednesday, June 3, 2009 - link
This article is kind of pointless beyond page 1 just cause you don't include ANY of the processors that used to be the best bang for the buck. Where's the E6600? the E8400? E6420?? the E7650??? Q6600? Seriously, showing us performance for new CPU's is pointless if you're not going to include the processors that sold the best in the past. I mean seriously, the E8400 is STILL the best bang for the buck around for many people and you didn't even include that... sad, just sad.Gary Key - Wednesday, June 3, 2009 - link
You can compare any of those processors to the 975 using our Bench tool - http://www.anandtech.com/bench/default.aspx?b=2">http://www.anandtech.com/bench/default.aspx?b=2 . :)lpcap - Wednesday, June 3, 2009 - link
I think for the world's most powerful laptop with the Core i7 975 go to:http://www.lpc-digital.com/store/3302695/product/c...">http://www.lpc-digital.com/store/3302695/product/c...
aigomorla - Wednesday, June 3, 2009 - link
:)I dont have anything bad to say about it.
Monster overclocker, im doing about 4.4ghz with 1.35vcore with full stability.
When i showed the 975 off a couple of months ago on the cpu and overclocking section, i told everyone the D0's were gonna be HOT.
Fulle - Wednesday, June 3, 2009 - link
Interesting... most 920s only can OC to about 4GHz at that voltage... even with the D0 stepping. Either you got lucky with your chip, or the 975 isn't as bad as I thought.Fulle - Wednesday, June 3, 2009 - link
Its fortunate for AMD that the vast majority of the games out there are NOT multithreaded, like FarCry 2... and for the majority of games out currently, they don't even scale with CPUs beyond 3 cores... which is evident if you look at the Phenom II X3 720's performance in Anand's benchies.It cracks me up to see some enthusiasts bashing Lynnfield. All things considered, the Lynnfield 2.8GHz CPU with HT will be the one to have for the best gaming frame rates. It has excellent 2 core performance with turbo mode, which will allow for top FPS in most games, and for those that are highly threaded, Graphics bottlenecks considered, it'll hang in pretty darn close to the i7s. Its almost as if Intel designed the chip specifically for hardcore gamers.
This 975/950 business seems lazy, however. Intel doesn't even try when AMD falls too far behind.
lifeblood - Wednesday, June 3, 2009 - link
"Intel really has no other external motivation to push for higher frequency parts, so we only see a bare minimum increase in specs here."If AMD fails the we will very quickly return to the days of overpriced and underpowered Pentium trash. When Intel has no competition they quit trying.