It is currently Fri Oct 31, 2014 1:27 pm

All times are UTC - 8 hours




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Undervolting a HD 7750
PostPosted: Sun Aug 11, 2013 6:38 am 
Offline

Joined: Tue Jun 11, 2013 9:46 am
Posts: 22
I'm trying to undervolt my HD 7750, however I am struggling to find any software to do this

MSI afterburner, Catalyst Control Centre & Sapphire TRIXX only allow me to adjust the power, not the voltages (adjusting the power down just slows down the card!)

ATI Tray tools is too old, and won't work on my system (despite hours of googling)

Any other suggestions?


Top
 Profile  
 
 Post subject: Re: Undervolting a HD 7750
PostPosted: Sun Aug 11, 2013 6:50 am 
Offline
SPCR News Editor

Joined: Thu Feb 10, 2005 11:20 am
Posts: 2175
Location: TN, USA
If your goal is to reduce the highest power draw you don't need to use any special 3rd party tool or app. Just go and turn down the PowerTune slider to -20% as seen in http://www.anandtech.com/show/4061/amds ... -hd-6950/9 and you'll cut the max power draw by 20%.

There really isn't any gain from changing the idle voltages, they are reduced by default and are tuned to a point that there is minimal or no gain to be had.

Oh and on the high end if you want to lower the max voltage without slowing down the card you are going to be looking at a BIOS editor like RBE but you'd be wasting your time, there is no free lunch. If you lower the voltage without slowing down the card you'll have corrupted graphics or your PC will lock up or your PC will reboot under load.

_________________
.
Please put a country in your profile if you haven't already.
This site is international but I'll assume you are in the US if you don't tell me otherwise.
RAID levels thread http://www.silentpcreview.com/forums/viewtopic.php?p=388987


Top
 Profile  
 
 Post subject: Re: Undervolting a HD 7750
PostPosted: Sun Aug 11, 2013 8:47 pm 
Offline

Joined: Mon Dec 28, 2009 1:42 am
Posts: 345
Location: Australia
As dhanson865 said, just lower the powertune slider and try and be happy with that. Your card simply may not have a chip to support voltage control through software (keeps the manufactuer's costs down).

dhanson865 wrote:
If you lower the voltage without slowing down the card you'll have corrupted graphics or your PC will lock up or your PC will reboot under load.

Many cards come with stock voltages higher than necessary. Eg. My 7950's came with stock settings of 925/1250 core/memory @ 1.09v, but I've got them running at 955/1250 @ 0.981v. That's a pretty decent 109mV undervolt, while also overclocking the GPU a little bit. I was also able to do similar with my previously owned cards. Do a stress test using Unigine Heaven to ensure stability under load.


Top
 Profile  
 
 Post subject: Re: Undervolting a HD 7750
PostPosted: Mon Aug 12, 2013 6:38 am 
Offline
SPCR News Editor

Joined: Thu Feb 10, 2005 11:20 am
Posts: 2175
Location: TN, USA
flemeister wrote:
Many cards come with stock voltages higher than necessary.


Yes for other cards that can be more common, but the 7750 is a 7770 that has already been power limited. The odds are stacked against you that there is any headroom on a 7750 that isn't easily controlled by PowerTune.

If you live in the artic or anartic circles and have a very cool environment or otherwise regularly keep your PC in ambient temps below 10 C (50 F) you'll have room to increase your voltage and to a smaller extent you'll have better stability and can thus reduce your voltage but the downward limit change is smaller than the upward limit change in cold ambient temps.

If you live in the hotter parts of the world and your ambient where the PC is is often above 30c (86 F) you'll gain stability by lowering the PowerTune limit and may have more headroom if you lower the voltage on the card but the high heat environment tightens the limits of how low or high the voltage can be making the undervolt option even harder to hit any noticeable power savings vs stock.

Experiment with the PowerTune slider in your hottest environment until you find the highest setting that improves performance (too high a PowerTune setting can actually slow down the video card). Turn it down even further if you want some margin for error, and further still if performance isn't your first priority.

Any tweaking you do will require thorough notes of ambient temps, case temps, GPU temps and lots of stress testing with graphics test that will show you FPS preferably with max, min, and avg values.

_________________
.
Please put a country in your profile if you haven't already.
This site is international but I'll assume you are in the US if you don't tell me otherwise.
RAID levels thread http://www.silentpcreview.com/forums/viewtopic.php?p=388987


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: Google [Bot], Yahoo [Bot] and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group