Can you undervolt a Radeon HD 5000-series?

[Brian]

A quick google search tells me you can undervolt a graphics card nowadays, "when supported by the graphics card", but there's not a lot of info out there, or on SPCR, on the topic.

I was able to roughly halve my CPU's power consumption with a 30% undervolt at stock clockspeed. Does anyone know what might be possible with a Radeon HD 5670-5770?

[Parappaman]

None of the video cards I ever used resisted at stock speeds on a lower voltage. Usually, GPUs are not made with the kind of tolerance you find on CPUs, as they have much stricter cooling and power to performance requirements. And, by the way, they usually offer some undervolting/underclocking at idle, so you might be better off concentrating on optimizing idle settings rather than full load ones. The HD5xxx series is unbeatable on this matter, so there is actually nothing to worry about, unlike what was the case with the HD48xx series, which was extremely hungry when idling but, with some effort, was capable of doing much better.

[Audiodude]

@Parappaman: I'm sorry, but it seems that you are mistaken.

If a Card is underclockable depends on the implemented voltage regulation circuit on the board. This circuit isn't the same on every implementation of a given design (GPU Chip type). So every Manufacturer decides for himself if the relevant circuits have a fixed programmed voltage or if the voltage can be altered!

For the new 5XXX Series you can get an idea of the Situation if you read the release Notes of the most used tool for bios tweaking -> The Radeon Bios Editor:

v 1.24

* Added 58x0 and 5970 GPU voltage control. I'd like to express my gratitude to VuurVOS who made this possible.
* Added memory voltage control where available (i.e. all cards that utilize a VT1165 in order to control memory voltage, such as 4890, 5870 and 5970 [as far as I know]).
* Added GPU voltage control for cards utilizing a L6788A chip. Most 4770s and 5770s use them. Hey, better late than never! Unfortunately, 5670 and 5750 reference design cards can not be supported because their UP6201 chip does not support external programming.
* Fixed subvendor-display on 5xx0 cards.

So most 5650 and 5750 Cards can't alter the voltages.
I just bought a Go!Green HD 5750 which has a completely different vr circuit and the tweakable VT1165 Chip. Which means that besides having a very low load power consumption, this card can probably be voltage tweaked.

Greetz Audiodude

[grandpatzer]

A quick google search tells me you can undervolt a graphics card nowadays, "when supported by the graphics card", but there's not a lot of info out there, or on SPCR, on the topic.

I was able to roughly halve my CPU's power consumption with a 30% undervolt at stock clockspeed. Does anyone know what might be possible with a Radeon HD 5670-5770?

I own a normal 5850, I downloaded MSI Afterburner, in settings I unlocked vcore and vcore monitoring.

I decreased the vcore to 1.00v, will run furmark for 30min now and compare temps with stock vcore.

edit---> anyone care to explain anygood software to see gpu stability?
run 1h loop of 3mark Vantage?

[Parappaman]

@Audiodude: you didn't read my post, otherwise you would have noted that I wrote undervolting/underclocking, not just undervolting. That's what the HD5xxx do: reduce power consumption either underclocking, or underclocking and undervolting, this without mentioning those Volterra thingies some use

@grandpatzer: nothing beats OCCT! Furmark is like hammering on the core, OCCT is like Chuck Norris'ing it
Did you keep load clocks the same? If so, that's an amazing result by this video card!

[flinx]

Parappaman is right - there's really not much you can improve on for the HD 5XXX series. The idle power usage beats anything else out there already. You might be able to save a watt or two during full load by undervolting, but could quickly run into limitations due to the tight tolerances involved. The 5850 is more forgiving than the 5870 though, due to the lower clock speed.

[Audiodude]

Sorry to disagree again,

undervolting in power mode (high 3D) will save a lot!
The HD 3850 I just retired dropped from 200W (full load/whole system) to 165W with undervolting. This was achieved with bios tweaking.
Idle power draw won't be that much affected by undervolting because of the already low clocks and hopefully low voltages but several watts are still possible.

Greetz Audiodude

[Brian]

I'm leaning towards the Sapphire HD 5670. Is there any way to tell what kind of VRM it has and whether the voltage will be adjustable?

[Ksanderash]

I'm leaning towards the Sapphire HD 5670. Is there any way to tell what kind of VRM it has and whether the voltage will be adjustable?

You can drop a look on the back side of the pcb, but...

Unfortunately, 5670 and 5750 reference design cards can not be supported because their UP6201 chip does not support external programming.

...and not only reference design cards, cause these uPI Semi chips are kind of dumpers on a electronic components market - they are cheap, and that's the main advantage for vendors.

[jack_in_the_box]

I was originally looking at a 5850, but considering how well the 5770 behaves...I was running through DAO at 157/300/0.8000 1600x1200, max everything for a hour, and even though it was about 20 FPS per FRAPs

On which card did you achieve the 157/300 @ 0.8V, a 5850 or a 5770 ? And did you still notice a drop in idle wattage with the lowered voltage?