Blue_Fire

We will indeed see.

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Aumotocnic:An Unfortunate Member Of The Overclock.net Insomniac Club

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NuclearCrap

Then don't retype. Link to it.

You can tell me that I'm wrong if you base everything on your theory. Tell me specifically where I'm wrong and back it up with proof. Until then, please don't go around the forums posting that you're tired of people not believing, it's not a good attitude to convince anybody.

I do understand the fact that the Pro is identical to XT in case you want to tell me that.

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FilthySanchez08

I'm interested in what this 003 guy is talking about too, because I thought the 2900pro was simply an underclocked 2900xt with a different BIOS...

003

Convincing people in advance is hard. On the 20th, it won't be.

Every single review of the HD3870 that includes the 2900 for testing used the cat 7.10 drivers on the 2900 and the beta 7.11 cats on the 3870.

The 3870 is quite literally, a die shrink of the R600 including UVD+ and an inferior 256-bit memory controller and 512-bit internal ring bus. What it does have though, is a higher core clock speed than the XT (775 vs 743) and a higher memory clock, but in the end (with regards to memory alone) the memory bandwidth is what matters and in the case of the 3870, a 256-bit memory bus with higher clocked memory is not enough to keep up with the 512-bit memory and 1024-bit internal ring bus on the 2900Pro/XT.

The memory bandwidth on a stock HD3870 is 72GB/s. The memory bandwidth on a stock XT is 105GB/s. The memory bandwidth on my 2900Pro with the memory @ 1035MHz is 125GB/s. The canadian website that overclocked the 3870 to 860MHz core and 2.7xGHz mem did not post a screenshot of GPU-Z. Even if they did I seriously doubt the bandwidth would have increased so drastically that it would surpass 125GB/s. The 256-bit memory bus and 512-bit internal ring bus are what kills the memory on the 3870. If ATI had used 512-bit gddr4 memory with a 1024-bit internal ring bus, the 2900 series would not have stood a chance against the 3870 and nvidia would be sweating a lot more than they are now. Unfortunately, they didn't.

Also it is important to know that the 2900Pro and the 2900XT are exactly the same card, they just have different bios'. The pro has tighter timings on the memory and when at the same core speed as the XT, it will beat the XT even with lower memory clocks, and this is consistantly the case. This is why it is better to use a volt modded pro bios rather than the volt modded XT bios, even when the XT bios will technically allow for higher memory clocks.

Moving on to the core.... it's pretty much the same as the R600, except a die shrink and the addition of UVD+ support. It also seems that right now, the 3870 refuses to budge an inch over 860mhz, which is very bad because a volt modded pro will easily hit 880MHz without breaking a sweat, possibly 900MHz or over, and that would be without question if you're on water cooling. I am on very good air and I know there are at least two people on XS to get 900 and 920mhz with volt mods on good air (and afaik, few others have tried, and the ones that have did not volt mod).

Hope this satisfies you...

QuickSkillz

So your telling me that a 2900pro at stock can keep up or beat a HD3870? I really doubt that considering the HD3870 is even faster/better than the 2900xt which beats out a 2900pro. The HD3750 also runs on a smaller process so it will run cooler which means better overclock potential and they fixed the AA bug too. I really cant wait until someone releases a BIOS that uncaps the HD3750's core though. I predict that once the core becomes uncapped and the new drivers are released that support the HD3750 than it will surpass the 8800GT by a decent amount.

EDIT: I always though that the core speed and actualy architecture of the card made the biggest difference in performance. From what ive seen/heard memory speed doesnt make nearly as much of a difference as the actual architecture/core speed of the card. Its like saying that DDR800 RAM would see a huge overall performance increase over DDR400 RAM which is not the case considering the processor does all of the work.

003

Read my post that is right behind yours. No a stock 2900pro can't beat an HD3870, btw. The "AA bug" is "fixed" in the 7.11 cats, and the reason AA is doing better on the 3870 than a stock 2900XT is because AA is done in the shaders (stream processors) on the R600 and RV670, and the shaders are clocked 1:1 with the core on both cards. Since the 3870 has a higher stock speed than the 2900XT, of course it is doing better on AA, also not to mention the fact it is using better drivers in all the current reviews.

003

That would of course be assuming the core is the limiting factor, which it's not on the R600 (the stream processors are immensely powerful if used correctly). The architecture of the R600 and RV670 are almost identical, minus the few things I have mentioned.

FilthySanchez08

that all sounds logical 003, but what would you say about the 1gb version of the 2900pro? why doesn't it beat the 8800gtx if the memory was the limiting factor?

I don't disagree with you however, the numbers don't lie, the 2900/3800s shaders are infinitely more powerful than the 8-series' shaders, there is just something holding it back that i can't put my finger on... Maybe its the Texture units or the ROPs, or maybe its because they perform all the processes on the shaders.... hell, maybe its because Nvidia engineers have worked hand-in-hand with almost every single major pc game title thats been released lately.... I dunno, but as soon as ATI figures their **** out, I think the 2900s and 3800s are going to be a hell of alot more powerful than they are now.

003

Memory is not really the limiting factor because the card's shaders are not being used at 100 % efficiency most of the time (drivers play a huge role in efficiency though, hopefully they continue to improve). I think QuickSkillz misunderstood me as it sounds like he interpreted my original comments about memory as "memory matters more than core", which is not true generally. I added in parentheses "with regards to memory alone" to my original post, so hopefully it is not confusing anymore.

I never said the 2900pro would beat the GTX, but it will be damn fast (faster than 3870) and we will see just what it can do on the 20th. I said that if the 3870 had used 512-bit gddr4 memory with a 1024-bit internal ring bus, THAT would beat even the most overclocked and tricked out 2900 ... assuming the 860mhz issue is fixed, and that would likely beat everything nvidia has to offer now and in the near future provided the memory speed and overclocking ability remained the same.

Perhaps ati will release a 512-bit w/ 1024-bit int. ring bus version later down the road? As in the past they have refreshed their cards from GDDR3 to GDDR4. One could always hope.

reptilematt

Man, after reading this stuff/**** I am so ******* happy that I bought a 3870
Are we heading back in time (2003-2005) where ATI's 9800 series came out of no where too absolutelly poon the FX stuff and even some of the 6800 attempts?