Vega Undervolting – Saviour, Voodoo or Useless? Self-test in long-term setting | Page 3

Benchmarks

The following are a series of benchmarks, each comparing 6 settings:

The factory settings
Manual undervoltage by 100mV
The “saving power” preset
The 24/7 “Eco” Fashion (Sweetspot)
Undervolting + simultaneous overclocking
Maximum overclocking

3D Mark Fire Strike

	Clock	Asic	Wall	GFX Score	Watt %	Score %	Score/Watt
Floor	1550	264	501	23812	100	100	47,53
-100mV	1590	257	494	24286	99	102	49,16
Eco	1300	199	408	21354	81	90	54,36
UV Eco	1500	178	393	23683	78	99	60,26
UV OC	1590	210	440	24938	88	105	56,78
Max OC	1710	340	635	26562	127	112	41,83

Red Dead Redemption 2 Benchmark 1440p “HUB Optimized” Settings

	Clock	Asic	Wall	Fps	Watt %	FPS %	FPS/Watt
Floor	1570	264	510	74,1	100	100	0,145
-100mV	1607	220	460	75,2	90	102	0,163
Eco	1460	198	420	70,9	82	96	0,169
UV Eco	1507	164	373	74,9	73	101	0,201
UV OC	1577	186	419	78,3	82	106	0,187
Max OC	1714	303	607	82,7	119	116	0,136

Forza Horizon 4 1440p “ultra” Preset

	Clock	Asic	Wall	Fps	Watt %	FPS %	FPS/Watt
Floor	1630	240	491	104	100	100	0,212
-100mV	1617	195	437	104	89	100	0,238
Eco	1503	198	443	99	90	95	0,223
UV Eco	1519	136	362	102	74	98	0,282
UV OC	1602	162	399	106	81	102	0,266
Max OC	1728	265	536	112	109	108	0,209

A Plague Tale: Innocence 1440p >high< (Einführung 60 Sek) (einführung=”” 60=””></ (Einführung 60 Sek)>

	Clock	Asic	Wall	Fps	Watt %	FPS %	FPS/Watt
Floor	1470	264	507	66,0	100	100	0,130
-100mV	1577	264	508	70,5	100	107	0,139
Eco	1230	198	406	57,0	80	86	0,140
UV Eco	1490	193	395	68,7	78	104	0,174
UV OC	1571	219	447	72,1	88	109	0,161
Max OC	1692	349	645	76,4	127	116	0,118

The measurements carried out lead to the following findings

Undervolting by 100mV brings 2-7% more FPS and 0-10% lower power consumption.
The Wattman power-saving mode costs 4-15% FPS, but brings 10-20% lower power consumption.
Undervolting + Overclocking brings 2-9% more FPS and 12-19% lower power consumption.
Maximum overclocking brings 8-16% more FPS, but leads to 9-27% higher power consumption.
The “Sweetspot” brings up to 5% more FPS and leads to 22-27% lower power consumption.

Summary and conclusion

Maximum overclocking is also maximally inefficient and for about 25% additional consumption there is hardly over 12% more FPS. In view of the exorbitant consumption of well over 600 W (total system) and the associated gigantic cooling effort, I can only expressly advise against this. The power-saving mode costs a lot of performance, because by reducing the power limit without simultaneously reducing the voltages, the higher P-States are no longer reached under load. As a result, the HBM may not clock up constantly and, in addition to lower FPS, frametime spikes can also occur, which feel very unpleasant.

For tinkerers, it is definitely worth looking for the sweetspot of his card. I suspect it will basically be around 1500 MHz at approx. 1 V voltage, which turned out to be the best compromise between power consumption and performance. Operated in the sweetspot and with optimized memory, the card is at least as fast as with factory settings and needs an average of approx. 25% less energy.

So what’s wrong with the myth of undervolting? Is it really possible to save power and are graphics cards with reduced voltage really faster? I can answer both with “yes”, but I also have to step on the euphoria brake in the same breath. Of course, 25% more performance and 25% lower energy consumption are not possible.

There are two options for undervolting: either you save electricity (same performance as factory settings with lower consumption) or you gain performance (more clock with the same consumption as with the factory settings). If you combine both options and optimize the memory at the same time, you can also increase the performance and at the same time reduce the consumption. However, the increase in performance always to a certain extent with the Increase in power consumption in scale. Undervolting from Vega makes it a much more efficient (or even faster) graphics card – but you can’t make it into the “power-generating 1080 Ti Killer”.

Pages: