496 MHs limitation per rig?

[tuncerbora]

Hi,

I have 8 RX 6900 XT working on my rig but can’t get more than 496 MHs, 62 MHs each. But on my second rig (exatly same mother board, ram and CPU) I have 6 cards total 353 MHs and RX 6900 XTs can get 64 MHs for each cards.

If I do the same OC to the first rig, some cards goes up to 64 MHs then some goes bellow to 60 MHs but total 496 MHs stay same.

How can I solve it ?

Thanks,
Bora

[Grea]

I am not aware of a MH/s limit per rig, plenty of 3090 based rigs out there demonstrating 500MH/s plus and my 8x6800s have crossed that threshold when pushed.

I don’t know enough about the 6900XTs specifically to assist with their high end limits. You may find more help here:

Advice for 6800, 6800xt and 6900 xt OC settings

You are behind on Kernel which added some benefits for your 6800s, but might actually complicate your 6800XT efforts. See posts by user oni running a non-XT/XT rig like yours on latest. In my opinion, you can be getting more out of the 6800’s on new kernel with your level of wattage. But the XT complication is one to navigate.

[tuncerbora]

Hi Grea,

Thank you very much for your reply, it lead me to a very good infos. If I am not mistaken you suggest me to update kernel, righ ?

Thanks

[Grea]

I’d pause on kernel upgrade for the time being. You want to confirm the F-state locking @1551 is appropriate for the 6900XT or if the new #72 kernel ignores them.

[tuncerbora]

I’m totally sorry but I really didn’t understand any of them If you could give more detail or direct me to a right point, it would be perfect.

When I search “f-state locking” I found irrelevant results

Thanks

[Grea]

Go to your Hive Shell or Direct console.

See the command and enter “and-info”.

See F state for your GPU and you want it to be the highest. I suspect yours is higher that 1551.

Hive Kernel #72 includes a feature which assists at least 6800’s in locking at highest. The thread I linked you to, has data which implies the locking may not be optimal for 6800XT and other cards in the series.

Note this is for a 6800, but the last few data lines have "f state marked at 1551.

[tuncerbora]

Thank you for those valuable infos. I put two output of two different rigs (first one is the one that I have problem)

First Rig

=== GPU 0, 25:00.0 Radeon RX 6900 XT 16368 MB ===
Bios: 113-D4121EXT-CO1
Core: 1250 MHz 662mV, Mem: 1049 MHz
PerfCtrl: manual, Load: 99%, MemLoad: 100%, Power: 131.0 W, Cap: 289 W
Core: 46°C, HotSpot: 52°C, Mem: 62°C, Fan: 60%, RPM: 2040
Core state: 1, clocks: 500 1250*
Mem state: 3, clocks: 96 456 673 1049*
SOC state: 1, clocks: 872 1200*
DCEF state: 1, clocks: 417 960* 1200
F state: 1, clocks: 1551 1941*
PCIE Link speed: n/a, PCIE Link width: n/a
Memory total: 16368.00 MB, used: 5834.19 MB, free: 10533.81 MB, type: Samsung GDDR6
VDDCR_SOC: 925mV, VDDCR_CPU: 1043mV

Second Rig

=== GPU 2, 34:00.0 Radeon RX 6900 XT 16368 MB ===
Bios: 113-D41201-XT
Core: 1250 MHz 662mV, Mem: 1066 MHz
PerfCtrl: manual, Load: 99%, MemLoad: 100%, Power: 135.0 W, Cap: 281 W
Core: 40°C, HotSpot: 47°C, Mem: 60°C, Fan: 60%, RPM: 1800
Core state: 1, clocks: 500 1250*
Mem state: 3, clocks: 96 456 673 1066*
SOC state: 1, clocks: 872 1200*
DCEF state: 1, clocks: 417 960* 1200
F state: 1, clocks: 1551 1941*
PCIE Link speed: n/a, PCIE Link width: n/a
Memory total: 16368.00 MB, used: 4705.25 MB, free: 11662.75 MB, type: Samsung GDDR6

[tuncerbora]

Any ideas ?