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Graphics Cards

Adept II

What are the FP64:FP32 ratios / what is the double precision power of the new 7900 series?

With AMD Radeon VII we got awesome FP64 power in consumer hardware.
The ratio was 1:4  (e.g. or and roundabout 3,4TFLOPS for double precision. It was a very powerful card, but i sold it for a good price at the end of year 2020.

With the 6900series the FP64:FP32 ratio was reduced to 1:16 and ends in roundabout 1,4TFLOPS (source

@amdSupport: But what ratio or what FP64 power has the new 7900 XT/XTX series?
Because of the dual issue "theory specs" we see roundabout 61TFLOPS in single precison (FP32) for the 7900 XTX.
When we calculate witout dual issue, it is roundabout 30,5TFLOPS.
With a theoretical 1:16 ratio it can be 3,8TFLOPS or just 1,9TFLOPS without dual issue for FP64.

When we see benchmark tools and starting discussions in forums, the guesses or figures are very low  0,9to1TFLOPS FP64 -> so just a 1:32 ratio??? What can the AMD Support can say to these figures?

Thank you.

1 Reply
Adept II

AMD Support hasn´t answered yet via mail, so i googled again.

Techpowerup has reduced or updated the figures in their database  - AMD Radeon RX 7900 XTX Specs | TechPowerUp GPU Database

The FP64 performance is theoretically just max. 1.919 TFLOPS with a "updated" 1:32 ratio regarding to the dual issue full FP32 61TFLOPS.

In real the FP64 will be ~0,9TFLOPS... (w/o dual issue).

Okay - the 7900 XTX is not so good for FP64... the RX6900/6950 will be better in that case.