Sapphire's response to ASIC quality

[futurefields]

Saw this while browsing Newegg reviews on Sapphire 7950's, I'm a bit behind on the whole ASIC score thing, has this all been settled already?



"Even with an ASIC value of 55.4%, it seemed pretty decent. Although, I'm starting to wonder if these card were intended for the Vapor-X line but had terrible ASIC score. I actually ordered the exact same card for a customer build and it had an ASIC value of 58%. Very poor ASIC quality (< 60%) for both cards that I bought."

Manufacturer Response:GPUZ "ASIC Quality" is not an actual measurement of PCB quality.

It is a calculation based on the voltages and clocks of the across the card and then compared to a reference design.

You will generally find that a card with lower "ASIC Quality" will overclock a lot better than cards with higher "ASIC Quality".

This is usually due to revised PCB designs with better VRM designs offer higher voltages and clocks which lower the "ASIC Quality" score.

This is supported and discussed in detail in many forums.
​

 

[Xarick]

If that were the case we would see higher overclocks on these more recent cards. When infact people seem to be having more trouble getting past 1150.

 

[f1sherman]

Allow me to quote myself quoting other people
http://forums.guru3d.com/showpost.php?p=4517024&postcount=10



Much confusion about ASIC quality and overclocking...

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AMD uses the following table to select VID depending on ASIC quality:

up to 2F90 (up to 75% quality) - 1.1750V
up to 34D0 (up to 80% quality) - 1.1125V
up to 3820 (up to 85% quality) - 1.0500V
up to 3A90 (up to 90% quality) - 1.0250V

http://forums.guru3d.com/showthread.php?p=4222314

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Actually, it does the opposite! We scale the voltage based on leakage, so the higher leakage parts use lower voltage and the lower leakage parts use a higher voltage - what this is does narrow the entire TDP range of the product.

Everything is qualified at worst case anyway; all the TDP calcs and the fan settings are completed on the wors case for the product range.

http://forum.beyond3d.com/showpost.php?p=1344008&postcount=29

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No, the nominal voltage is 1.165V, however the higher leakage parts do not need as much voltage to run at those speeds.

http://forum.beyond3d.com/showpost.php?p=1344083&postcount=33
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Lets recap:

Higher leakage <--> High ASIC <--> Lower voltage needed to reach MHz <-> Lower VID

same TDP as

Lower leakage card <--> High Vid <--> Low ASIC <--> High voltage needed to reach MHz

Which ones can clock higher?

Pure luck.

Low ASIC can take higher voltage. But it NEEDS higher voltage, and will produce same heat as higher ASIC on lower voltage/same MHz.

 

[BallaTheFeared]

Basically all boost 7950s are 1.25v, giving them a lower asic quality score?

That can't be right, since all 7950s are 1.25v if they're boost, and my two TF3s had different scores even though they had the same voltage and clock speed (1.25v/960Mhz).

 

[aaksheytalwar]

Basically all boost 7950s are 1.25v, giving them a lower asic quality score?

That can't be right, since all 7950s are 1.25v if they're boost, and my two TF3s had different scores even though they had the same voltage and clock speed (1.25v/960Mhz).

How is that relevant? Cards have different scores.

 

[Silverforce11]

Basically all boost 7950s are 1.25v, giving them a lower asic quality score?

That can't be right, since all 7950s are 1.25v if they're boost, and my two TF3s had different scores even though they had the same voltage and clock speed (1.25v/960Mhz).

Wait.. u have TWO 7950s now? Any chance to report your horrendous experience with CF?

My 7950 has 89% ASIC, and a default vcore of 1.075, with 880mhz core default clocks.

Less vcore = lower power use in gaming, so since theres no correlation with lower asic % leading to better OCs.. go for highest asic % for cheaper power bills & less heat.

 

[BallaTheFeared]

How is that relevant? Cards have different scores.

It is a calculation based on the voltages and clocks of the across the card and then compared to a reference design.

Wait.. u have TWO 7950s now? Any chance to report your horrendous experience with CF?

My 7950 has 89% ASIC, and a default vcore of 1.075, with 880mhz core default clocks.

Less vcore = lower power use in gaming, so since theres no correlation with lower asic % leading to better OCs.. go for highest asic % for cheaper power bills & less heat.

No I had a bad card, it was replaced. My ability to take punishment only goes so far. ^_^

 

[Cloudfire777]

From hardwareluxxx.de.