Thursday, January 5th 2012
AMD Denies Hidden GCN CUs in Tahiti
Over the past few days, we were hearing rumors from many quarters that AMD's "Tahiti" high-performance GPU may have been a deviation from an older specification, and that it really has 2304 stream processors spread across 40 GCN compute units (CUs), instead of the 32 the Radeon HD 7970 ended up with. Both AMD and NVIDIA create more redundant components on their chips than their SKUs end up getting, so they could increase yields, it's a process commonly known as "harvesting".
On Tuesday, AMD quashed the rumor in an e-mail to Bright Side of News, in which it said that Tahiti XT (Radeon HD 7970) makes use of all the CUs there are, on the chip. The 40 CU / 2308 SP rumor gained some weight with the fact that since AMD is venturing into unknown territory (TSMC's 28 nm process, built after quite some delays and failures), it could do some heavy harvesting. Examples of harvesting in recent past include Intel Sandy Bridge-E Core i7 processors, which use only up to 6 out of 8 cores on the silicon, and only up to 15 MB out of 20 MB available on it; and GeForce GTX 480, which used only 480 out of 512 CUDA cores available on the GF100 GPU.
Source:
Bright Side of News
On Tuesday, AMD quashed the rumor in an e-mail to Bright Side of News, in which it said that Tahiti XT (Radeon HD 7970) makes use of all the CUs there are, on the chip. The 40 CU / 2308 SP rumor gained some weight with the fact that since AMD is venturing into unknown territory (TSMC's 28 nm process, built after quite some delays and failures), it could do some heavy harvesting. Examples of harvesting in recent past include Intel Sandy Bridge-E Core i7 processors, which use only up to 6 out of 8 cores on the silicon, and only up to 15 MB out of 20 MB available on it; and GeForce GTX 480, which used only 480 out of 512 CUDA cores available on the GF100 GPU.
52 Comments on AMD Denies Hidden GCN CUs in Tahiti
Uh, by the way, which company has the most powerful graphics card for the last 3 years or so?
That AMD didn't have a single-GPU card that competed directly with the GTX 580 doesn't mean squat if they still put out the fastest single graphics card. In your opinion, nVidia is better because of that single little detail. Guess what. The vast majority of users don't care. The vast majority of users won't spend $550 on a card. And there are AMD cards priced similarly to the GTX 580 that are very competitive, such as the 6870x2. Oh wait, for the same money that card outperforms the GTX 580. Except it has 2 GPUs.
So in your opinion, that makes nVidia a maker of vastly superior hardware? You are smoking some very funny stuff dude.What do you mean, a sidegrade. The 7970 is quite a bit faster than a 580.
tell me is 8% "worth" the upgrade for me? thats what i mean side grade :rolleyes:
dont fanboy crap on me, im on my side which is best bang for my money and currently not worth upgrading
It's OK little feller, it happens.
You should know the lower resolutions are all CPU bound, even moreso with these monster graphics cards.
Let's take some slightly more reasonable examples, and PLEASE keep in mind these were done with beta drivers with lots of kinks left in them, which explains why the "summary" scores are lower than they should be. Yes, I am accusing you of intentionally misleading with your post. Oh and it looks like you can't read either, given that my fanboi comment was clearly as a reply to that PremoGS person.
BF3 1080p, 20% faster:
BF3 2560x1600, 23.7% faster:
Summary, 1080p, 11% faster:
Summary 2560x1600, 19% faster:
So yeah, I think 20% faster (on beta drivers) is an upgrade, not a sidegrade. Is it one *I* would personally make from a gtx 580? That's another question entirely, but certainly to call the 7970 an equal to the 580 is misleading at best.
having said that, i doubt there really are disabled units and on the car analogy, this would be as if they said there's a 2.5 turbo under the hood when there really is a naturally aspirated 3.5.
not trying to mislead ppl clearly numbers showed 7970 is better, and i definitely recommend it for ppl trying to choose b/n 580 and 7970 but for those who have 580? no bc i would wait what green team has to offer
and my fanboy comment is meant for anybody trying to start pointless argument which team is better
I'm only interested in OC'ing these things like a boss. Going to wait for some non-reference variants that have factory OC and some quiet coolers :D
Fact the 7970 overclocks like a boss so will kepler?
Will you be satisfied when W1zzard reviews a sapphire card @ 1335Mhz and is 30% faster
Your epeen is no longer the biggest just accept
BUT it's not a sidegrade either, the card has far more potential under the hood than it shows in reviews and the reason is the HUGE overclockability.
this most definitely is not a sidegrade, but an upgrade. personal preferences don't matter.