AMD sent HD 4830 samples to reviewers with missing shaders

[in_awe]

No, a comparison between HD 4830 (with the old defective BIOS), the HD 4830 (with its proper BIOS) and HD 4850 was made. End result effectively is the comparison between RV770LE 560, 640, and RV770Pro 800 SP.

To make things ideal, a reference AMD HD 4830 board was compared to the reference HD 4850 board (same PCB layout and components).

Check out the second half of the Testing section in the first post of this thread. W1zzard shows the results of gradually disabling the SIMD units on a 4850.

 

[W1zzard]

i still have the card. it doesnt matter for this part of the conversation anyway.

at this time i'm not willing to disclose how to reduce the number of shaders

edit: thread has been cleaned up

edit2: there is no "program" to do it

 

[lemonadesoda]

W1zzard,

How did you disable SIMD units on the fly? You mention a register, so I assume you edited that somehow, but what program did you use? I found it very interesting that the AMD 4830 used significantly less power at idle than the PowerColor 4830. Only about 25% of my time on my PC is spent on gaming. My biggest gripe with the 48xx cards (and now the 47xx cards too by the looks of the initial reviews) is their idle power usage in comparison with a 3850 (my current card) or a 4670. If SIMD units could be turned off on the fly on a 4850 or 4870, say down to 4670 levels, and there was a corresponding idle power usage decrease, that would be perfect, even if a restart was required to re-enable them. The power of a high end card when needed, the low power usage of a low end card when not.

Thanks in advance for any information you can provide.

I welcome your question. Never mind about it being an old thread. It is relevant and topical, and your question is better placed here than starting a new thread and having to do a whole lot of explaining. I hope w1z can share some insights...

And welcome to TPU.

i still have the card. it doesnt matter for this part of the conversation anyway.

at this time i'm not willing to disclose how to reduce the number of shaders

Shady dealer

 

[in_awe]

i still have the card. it doesnt matter for this part of the conversation anyway.

at this time i'm not willing to disclose how to reduce the number of shaders

edit: thread has been cleaned up

edit2: there is no "program" to do it

Thank you for the reply W1zzard (and for cleaning up the thread). Do you plan to release that information at some point in the future, or perhaps include it as part of a tweaking program? The low-power freaks like me would greatly appreciate it. Or are you planning on keeping it to yourself forever? (cue evil laugh)

Of course, I just realized it may be a hardware hack, which would exclude me from using it. I'm completely inept when it comes to using a soldering iron.

 

[W1zzard]

Thank you for the reply W1zzard (and for cleaning up the thread). Do you plan to release that information at some point in the future, or perhaps include it as part of a tweaking program? The low-power freaks like me would greatly appreciate it. Or are you planning on keeping it to yourself forever? (cue evil laugh)

Of course, I just realized it may be a hardware hack, which would exclude me from using it. I'm completely inept when it comes to using a soldering iron.

as tweaking program might be possible in the future.

it's not a hardware hack, it can be done in realtime, even while the card is rendering.

i doubt there is that much to be gained power consumption wise. it is definitely not 50% for going to half the shaders. educated guess might be 5%

 

[in_awe]

as tweaking program might be possible in the future.

it's not a hardware hack, it can be done in realtime, even while the card is rendering.

i doubt there is that much to be gained power consumption wise. it is definitely not 50% for going to half the shaders. educated guess might be 5%

OK, thanks. I was just guessing on the idle power usage based on your original AMD 4830 review (with only 560 shaders) versus your PowerColor 4830 review. The AMD 4830's idle usage was close to 4670 levels. Achieving 4670 levels with a 4850 or one of the new 4770s would be awesome.