• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

PSU for Crossfire 6950 and would too weak cause Micro Stutter?

wadded

wadded

wadded

Associate
Joined
17 Nov 2008
Posts
12
Hi All,

I've recently upgraded my Mobo/CPU/RAM/GPU for Crossfire (Rig in sig).

As an Eyefinity User (5760*1080), I've struggled to find a Single Card that will provide enough power to run games such as F1 2011/BF3 at High/Ultra levels.

So I've gone with Crossfire (2x 6950's) which has improved my FPS, however I seem to be witnessing the dreaded Micro Stutter.

I have browsed many forums and it seems there is possibly no solution. :mad:

One potential flaw in my rig is my PSU 700W (Coolermaster Real Power T700
product.php
). It's 12V rail supports Peak Current of 19A.

This could have been a grave mistake on my part by looking to save money on a replacement PSU. I did run the figures into a calculator but only took into account Total Watts for the whole rig.

Does anybody have any advice and/or confirm if weak PSU's could be the cause of Micro Stutter? A few other sites appear to state this could be a symptom, but I don't necessarily want to just throw more money at the rig unless I know for sure I have a chance of resolving the issue.

I'm really disappointed to get this far to achieve the FPS I've so sought after, to fail at the final hurdle..

Any help and advice would be really appreciated...Likewise on replacement PSU's. (800w-850w Modular pref)

Thx
 
Micro-stutter will always be there when seperate GPUs are involved; moreso when they are on different cards.

You must remember that micro-stutter can manifest in a few ways, but more often it is where a high Frame rate drops just momentarily. Say 100FPS, then a drop to 10FPS every 1000 frames. So every 10secs you will have visual stutter/lag.

Most important thing is minimum FPS. Not maximum or average. If you have min FPS over 40, you're doing well...imho.

Good read: http://techreport.com/articles.x/21516
 
wadded said:
he dreaded Micro Stutter.

I have browsed many forums and it seems there is possibly no solution. :mad:
Click to expand...

That's the nature of the beast I'm afraid. As f00f1ght0r rather splendidly put it things such as microstutter and flickering are part and parcel of a multiple GPU system.

Sadly it would seem that people such as f00f1ght0r "R rong" and it doesn't really happen. That is, at least, according to the hundreds of people that run a multi GPU set up and "Iv as no is problem is".

*sigh*
 
Most FPS readers (i.e. OBD or FRAPS) won't poll the stutter as the sample is too diluted, so even a time referenced graph won't show it. You need the correct software to measure it as the article suggests.

Funny thing is, most software won't detect it, but your eyes will. I find that annoying as well as screen tearing.

Interestingly, I haven't noticed it anywhere near as much with the HD6990 as I did with 6970XF, 5970XF, etc.

Perhaps dual GPU cards are the way forward?

If you test your system it will likely report some stupidly high FPS value, but you should be more concerned about the minimum FPS *if it polls at the desired frequency*. No point having a card/system capable of 100000000FPS if every 10secs it drops to 1FPS. It would be unplayable. Whilst you could very easily game on a system that gives 100FPS if it drops to 60FPS minimum.
 
Last edited:
f00f1ght0r said:
Most FPS readers (i.e. OBD or FRAPS) won't poll the stutter as the sample is too diluted, so even a time referenced graph won't show it. You need the correct software to measure it as the article suggests.

Funny thing is, most software won't detect it, but your eyes will. I find that annoying as well as screen tearing.

Interestingly, I haven't noticed it anywhere near as much with the HD6990 as I did with 6970XF, 5970XF, etc.

Perhaps dual GPU cards are the way forward?
Click to expand...

Nah. IMO they are a little better, but I think that could simply be down to the fact that they're "hard wired" together and the creators of such cards (Nvidia and AMD) write drivers specifically for those cards.

I mean you need to remember that multi GPU cards are the willy wavers for AMD and Nvidia and thus it's important they get them firing on all cylinders.
 
Hmm but it doesn't add up.

I had a crossfire setup about 2 years ago (4870 x 2). No evidence of micro stutter there. Only reason I switched back to single was to reduce power and heat, that and the single 5870 offered similar performance to crossfire 4870's.

Unless my eyes are failing me now, the comparison between crossfire 4870 and 6950 is night and day.

I do hear your point though that sudden changes in FPS will make the issue more visible.

It just doesn't seem viable that this should be just 'accepted' as is, when you consider the cost!

Do I just take a risk and go with Crossfire approved PSU over my existing PSU?
 
Hello i dont know a lot about microstutter etc, but i have asus 6970's in xfire and i play bf3 and i never get any what so ever at all! I run fraps most the time and i get 65fps adv, and id say 50fps min in heavy heavy action! However sometimes it can jump up into the 90+ in indoor area's.
I leave AA off, if i set it to x2 or x4 then my adv fps drops to 45/50 and my min is 31/32 ish, i have everything else set to ultra settings and run 1920x1080 res!

On a side note, sometimes i load single player up and i get 3fps i have to drop the settings to 640x480 everything low, apply the setting my fps hits 300, then set it back to what i had before, (1920x1080 in ultra) and then its ok, anyone else get this problem?
 
Microstutter has been remarked to be only visible to certain people who are particularly observant/have excellent vision. (There's no easy way of phrasing this without making it sound like a superhero ability lol).

Basically, if you have deteriorated vision, or have genetically poorer eye sight, you might not ever notice it - whilst it is stated that humans can detect 24FPS on video/films, some can only manage as low as 17-18, whilst others have been proven to detect up to 30, dependent on the individual.

Micro-stutter will always occur with dual GPUs. There is no doubt of this.
 
Well i dont know how good or bad my eye sight is, i know i had 20/20 vision on my last eye test about 3years ok, i dont need glasses or anything like that, but ive had xfire setup a few times i had 3870 xfire then 5870 xfire now 6970 xfire and my eyes have never picked any up that i can remeber! However im not saying it hasnt happened just i havent spotted it.
 
Turb3k said:
Well i dont know how good or bad my eye sight is, i know i had 20/20 vision on my last eye test about 3years ok, i dont need glasses or anything like that, but ive had xfire setup a few times i had 3870 xfire then 5870 xfire now 6970 xfire and my eyes have never picked any up that i can remeber! However im not saying it hasnt happened just i havent spotted it.
Click to expand...

I've noticed it in all rigs - at first it looked like the computer loading briefly. But when you realise what you're seeing is actually micro-stutter, then it all falls into place.
 
I solved microstutter on my xfire setup but using vsync. That removed it constantly.

I can run 1080p ultra with 4xaa and only drop to 50fps during the most intensive moments. ;)
 
You must log in or register to reply here.
Back
Top Bottom