AMD sent HD 4830 samples to reviewers with missing shaders

[eidairaman1]

no, possible etching of the PCB was done either on purpose or accidentally, that or the cards were locked further because of Shader Flaws in the earliest batches, just managed to slip thru the cracks, but no worries, if the card doesnt meet the specs advertised you can take the part back and ask for your money back, but with this set of cards, i say until AMD gets the bugs out, i say go with the 4850 or 4870.

[W1zzard]

Originally Posted by alexp999

So if I'm reading this right. All HD4830 GPUs are hard locked to 640SP, but for some reason the ati cards shipped with a bios locked to 560SP?
So a simple flash sets it back at 640SP?

Yes. Whether some kind of BIOS mod can be used on HD 4830 to go from 640 -> 800 is unknown, but I highly doubt it.

[suraswami]

Originally Posted by W1zzard

Yes. Whether some kind of BIOS mod can be used on HD 4830 to go from 640 -> 800 is unknown, but I highly doubt it.

But you are the Wiz, you can make it

[W1zzard]

bump for statement by amd

Originally Posted by W1zzard

bump for statement by amd

pheew ... .

btw how do you disable SIMD ?

[lemonadesoda]

BUMP and thanks to w1zz for identifing the issue, informing AMD, getting a fix, and posting it!



What a champ...

[newtekie1]

Ah, so it was just a faulty BIOS issue.

Does that mean a re-review of the ATi card is coming? Or did you already have to send the card back? Any chance boards slipped into the retail market with the defect?

I wonder if they flashed the BIOS with the locked pipes to possible test an even lower end configuration for the 4800 series. Maybe we will see an HD4810?

Originally Posted by newtekie1

I wonder if they flashed the BIOS with the locked pipes to possible test an even lower end configuration for the 4800 series. Maybe we will see an HD4810?

and flash it to HD4830, or even 4850 !! Yay !!!

[W1zzard]

Originally Posted by newtekie1

Does that mean a re-review of the ATi card is coming? Or did you already have to send the card back? Any chance boards slipped into the retail market with the defect?

nah already had enough troubles with the damn hd 4830 .. look at the powercolor review for the performance, look at the amd review for the rest

[newtekie1]

Originally Posted by W1zzard

nah already had enough troubles with the damn hd 4830 .. look at the powercolor review for the performance, look at the amd review for the rest

Cool, thats what I figured.

Off Topic: Any tips on overclocking an HD4670? I bought the same one you reviewed from HIS, but I can't overclock it at all via software. I tried using AMD's GPU Clock Tool (0.9.8), but any time I adjust the core frequency at all the computer just locks up.

[wolf]

Originally Posted by W1zzard

As you can see, the FPS changes linearly with the number of shaders in the GPU. Please note that this is data from some real empiric testing. All those ten tests were performed with a real running HD 4850 (running at HD 4830 clocks for better comparability), without reboot in between, shader count was changed on the fly.

It is however possible to temporarily disable _additional_ fuses to reduce the shader count even further.

how did you manage to alter the usable shader count without rebooting W1z?

[rui]

Hi W1zzard,

Where can I download the "560" shaders 4830 BIOS, or can you share this BIOS with us? Thanks!

[Chicco85]

I have a 4830 ES that has only 560 stream processor enabled. Flashed with the bios, i went up to 640 without problem (perlin noise test from 180 to 250 fps...).

Thanks a lot W1zzard.

Originally Posted by W1zzard

Yes. Whether some kind of BIOS mod can be used on HD 4830 to go from 640 -> 800 is unknown, but I highly doubt it.

AMD said to me that the alu are physically disable.

[Hayder_Master]

Originally Posted by Solaris17

Intriguing ill see if we have a sample.

Do you think their were 2 different batches? 560SP for internal testing until they finally decided on a shippable 640SP?

that is really good point

[Hayder_Master]

ohh , w1zzard really nice work , ati now very thankful to you im sure

[Betty (Kung Pow)]

BUMP

Sry for it but this one catched my interest.

When you found this out, did you see if there were any diffrence in heat as well between the cards?

Or even better, if there were any differ in current consumption?

[W1zzard]

technically there is less heat output and lower power draw. i seriously doubt you will be able to measure the temperature difference with today's in-gpu sensors. the lower power draw should show up on any half decent watt meter

[Betty (Kung Pow)]

Originally Posted by W1zzard

technically there is less heat output and lower power draw. i seriously doubt you will be able to measure the temperature difference with today's in-gpu sensors. the lower power draw should show up on any half decent watt meter

Thx.

I was just thinking if this could be done on laptops to reduce power consumption, or if its already done by the power saving mechanics?

[in_awe]

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.

[btarunr]

Originally Posted by in_awe

W1zzard,

How did you disable SIMD units on the fly?

He didn't disable it, he received a sample that came with a defective BIOS that used only 560 SPs.

[eidairaman1]

wow bring back a topic that has been dead and over with for some time now. Attn All 4830s have the 640 Shaders. May we please close this topic?

[in_awe]

Originally Posted by btarunr

He didn't disable it, he received a sample that came with a defective BIOS that used only 560 SPs.

Wow... super-fast reply! Yes, his test unit did come with only 560 SPs enabled, but he then went on to gradually disable SIMD units on a 4850 to see if there was a linear decrease in performance. I'm wondering how he disabled them on the 4850.

[[I.R.A]_FBi]

Originally Posted by in_awe

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.

Couldnt you edit the bios so the idle clocks are lower?

[btarunr]

Originally Posted by in_awe

Wow... super-fast reply! Yes, his test unit did come with only 560 SPs enabled, but he then went on to gradually disable SIMD units on a 4850 to see if there was a linear decrease in performance. I'm wondering how he disabled them on the 4850.

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).

[in_awe]

eidairaman1,

Sorry to have bumped an old post. I just stumbled on it... late to the party. I tried to find some discussion of this in other posts or on other sites, but it looks like W1zzard is the only person who took his testing to this level. I'm not actually interested in how many shaders a 4830 has, but rather in being able to disable shader units on any 48xx card in order to reduce idle power consumption. W1zzard was able to disable them on a 4850 without even rebooting... I'm just hoping to benefit from his advanced knowledge.


[I.R.A]_FBi,

Lowering the idle clocks does help, but not enough. I bought a 4850 when they first came out and tried super-low settings. That was when the BIOSes were shipping with the wrong settings in them. The idle power usage never came anywhere near 3850 levels though. W1zzards testing potentially opens up a new way to lower power usage.