AMD RX 7900XTX and RX 7900XT Reviews

[Pete]

Joker Productions with a nice comparision between 7900XTX and 4080 using a overlay:

No clue which clock rate this overlay reads but in F1 22 the 7900XTX can clock under 2000MHz. That explains the low performance in a few games:

Why does the 7900 show 0.5-2.5GB more “VRAM used” than the 4800, especially with RT? It also clocks way lower in some RT tests vs. the rasterized test.

Guardians of the Galaxy and F1 2022 show the biggest VRAM deltas. It clocks quite high in both Guardians tests but is much slower than the 4800 in both. It clocks quite low in both F1 tests yet is only slow with RT.

 

[Below2D]

Why does the 7900 show 0.5-2.5GB more “VRAM used” than the 4800, especially with RT? It also clocks way lower in some RT tests vs. the rasterized test.

Likely VRAM allocation. Cards with more VRAM almost always always show a higher "usage" than those with less despite running identical settings and resolution.

 

[TopSpoiler]

Why does the 7900 show 0.5-2.5GB more “VRAM used” than the 4800, especially with RT?

RDNA's RT implementation requires >2x BLAS memory compared to Nvidia's.
Seems AMD didn't fixed it.

Table from https://tellusim.com/rt-anim/

 

[Digidi]

7900xtx is an oc Monster: 3.2 ghz…

ASUS Radeon RX 7900 XTX TUF OC Review - Amazing Overclocking

The ASUS Radeon RX 7900 XTX offers fantastic overclocking potential. Thanks to a triple 8-pin power input, the XTX is no longer power-limited, and the amazing quad-slot cooler ensures the card stays cool and quiet at all times. After manual overclocking, the performance uplift to RTX 4080 was an...

www.techpowerup.com

 

[Below2D]

7900xtx is an oc Monster: 3.2 ghz…

ASUS Radeon RX 7900 XTX TUF OC Review - Amazing Overclocking

The ASUS Radeon RX 7900 XTX offers fantastic overclocking potential. Thanks to a triple 8-pin power input, the XTX is no longer power-limited, and the amazing quad-slot cooler ensures the card stays cool and quiet at all times. After manual overclocking, the performance uplift to RTX 4080 was an...

www.techpowerup.com

Too bad they don't show power consumption numbers. Plus the 4090 in their test uses a 5800X. They updated the 4080 to a 13900K but didn't bother updating the 4090.

 

[trinibwoy]

HWUB pulled no punches in their 7900XT review. Brutal.

 

[techuse]

AMD and Nvidia are doing their absolute best to dissuade gamers from upgrading. I’ve upgraded almost every major performance jump since 9800 pro days but here I am going on 7 years without an upgrade and little desire to do so.

 

[gamervivek]

Joker Productions with a nice comparision between 7900XTX and 4080 using a overlay:

No clue which clock rate this overlay reads but in F1 22 the 7900XTX can clock under 2000MHz. That explains the low performance in a few games:

Wow, the clockspeeds are atrocious in that video with F1 RT. Is it thermally throttling when the core temps are in 80s, because it dropped down to 1.5GHz which is OG Vega territory.

I found another video with overlay, though not as reputable channel as Joker's, showing almost 500-600MHz of clock deficit for 7900XTX against 4090 in rasterized games.

TPU's review otoh showed 2.6GHz median, though again AMD's clocks are a bit confusing this gen.

AMD Radeon RX 7900 XTX Review - Disrupting the GeForce RTX 4080

Navi 31 is here! The new $999 Radeon RX 7900 XTX in this review is AMD's new flagship card based on the wonderful chiplet technology that made the Ryzen Effect possible. In our testing we can confirm that the new RX 7900 XTX is indeed faster than the GeForce RTX 4080, but only with RT disabled.

www.techpowerup.com

 

[PSman1700]

AMD and Nvidia are doing their absolute best to dissuade gamers from upgrading. I’ve upgraded almost every major performance jump since 9800 pro days but here I am going on 7 years without an upgrade and little desire to do so.

Seems thats a trend not just by nv and amd or the pc space.

 

[TopSpoiler]

I found another video with overlay, though not as reputable channel as Joker's, showing almost 500-600MHz of clock deficit for 7900XTX against 4090 in rasterized games.

AMD didn't changed their power sensor reading as the total board power? The overlay value never reachs 355W at all.

 

[DavidGraham]

AMD didn't changed their power sensor reading as the total board power? The overlay value never reachs 355W at all.

No they didn't. On that subject, Igor tested the power with his advanced equipment, and found these results, he measures power of all tested games, then averages the values: 7900XTX consumed 26% more power than 4080.


He breaks down the power for raster and ray traced games as well, in RT the 7900XTX burns 20% more power, but in raster it burns 30% more.

AMD Radeon RX 7900XTX and RX 7900XT Review - One giant step forward and one step sideways | Page 6 | igor´sLAB

The time has finally come and after a lot of theory and unboxing in the run-up, we can finally test what the new Radeon RX 7900XTX and RX 7900XT can really do and where there might even be further…

www.igorslab.de

 

[davis.anthony]

It's the 2900XT all over again.

 

[troyan]

I must say that it is so strange that a company is using a 10 years old approach to increase compute performance when this approach has been discarded by nVidia after 1 and 1/2 generations.

 

[hoom]

It's the 2900XTX all over again.

If that means RV770 all over again a bit later it may be worth the pain now?

 

[Cyan]

nice review and overall nice conclusion

 

[Henry swagger]

I must say that it is so strange that a company is using a 10 years old approach to increase compute performance when this approach has been discarded by nVidia after 1 and 1/2 generations.

What approach ?

 

[Henry swagger]

No they didn't. On that subject, Igor tested the power with his advanced equipment, and found these results, he measures power of all tested games, then averages the values: 7900XTX consumed 26% more power than 4080.

View attachment 7805
He breaks down the power for raster and ray traced games as well, in RT the 7900XTX burns 20% more power, but in raster it burns 30% more.

View attachment 7809
View attachment 7810

AMD Radeon RX 7900XTX and RX 7900XT Review - One giant step forward and one step sideways | Page 6 | igor´sLAB

The time has finally come and after a lot of theory and unboxing in the run-up, we can finally test what the new Radeon RX 7900XTX and RX 7900XT can really do and where there might even be further…

www.igorslab.de

8nm ampere more efficient in rt than 5nm 7900 xt

 

[JoeJ]

nice review and overall nice conclusion

hihi, Barbie girl enthusiast gamer niche : )

RDNA's RT implementation requires >2x BLAS memory compared to Nvidia's.
Seems AMD didn't fixed it.

I take this as a hint NV uses treelet compression, with spatial branches of BVH requiring only low precision for the bounding boxes.
RDNA2 instructions would not allow this, due to precision not being flexible, afaict.

Would be very interesting to see Intels numbers in this regard, too improve the speculations. Could be just a matter of branching factor too, which we only know for AMD to be 4.

 

[troyan]

What approach ?

Relying on some kind of ILP to schedule more instructions without adding more hardware scheduler and dispatcher units. nVidia has done that with GF104 and Kepler: https://www.anandtech.com/show/3809/nvidias-geforce-gtx-460-the-200-king/2

 

[Henry swagger]

Relying on some kind of ILP to schedule more instructions without adding more hardware scheduler and dispatcher units. nVidia has done that with GF104 and Kepler: https://www.anandtech.com/show/3809/nvidias-geforce-gtx-460-the-200-king/2

True .. they are wasting 5nm density if they dnot use it like nvidia