Case Mod - In Progress Passively air-cooled GTX570 SLI - April, 2013

Love the awesome craziness of this, this is some badass modding, congrats.

Got to admit using tower coolers on GPU's has crossed my mind before now awesome to see someone do it & do it successfully, extremely good stuff jippa.

Awesome intro.

 

Thanks.

 

This is insane and we all love you for that! Great work!

 

Have you tried to put some isolation, e.g. Aluminum foil around the SLI cables?
I heard from someone using a PCIe riser cable on his GPU that using aluminum solved his problems.

 

Using SLI in two slow-ass cards; I've seen Microstutter; it's nothing like what you're experiencing, Graphically ;everything appears okay, but the framerate is choppy and uneven, giving the impression that it's running slower than it is. Hence "Micro-Stutter." (Or Microlag as you call it.)

What you're getting would be more a sign that something isn't rendering correctly, but it would be more uniform were it a problem with the GPU, my best suggestion is trying to prevent Interference, elAwesome's idea of creating a quick shield out of Aluminium foil is worth a shot, it'd definitely help damp-down some of the interference were that the case.

Try using the second GPU for your video output, see if that changes anything. SLI doesn't really care which GPU is working as output, just so long as it's connected before system startup.

As for the reason you don't see Graphical artefacts on the Desktop; Drivers won't engage the second card till actual 3D load is placed upon it, by a game or some other program that calls DirectX. - This means that GPU1 does all the usual desktop odds and ends, while GPU2 is often at absolute idle. It's a power saving feature, of sorts.

 

Could it be because of the latency between the 2 cards caused by longer than normal connection distances? I mean, the cards are pretty far away from the motherboard, and also from each other. Also have you tried changing out your video cable? I've seen this "blue shift" on bad dvi or vga cables too.

 

Hello again!

I have already tried to wrap the SLI bridge into aluminum foil. It is actually wrapped into aluminum foil at this very moment, too. The picture does not get any better. The foil is well grounded to the PC case and I use plenty of it, be sure about that. I will try to exchange the video cable, although its a factory Dell DVI-D cable bundled to the DELL U2711.

Best!

jippa

 

Did you check the output and tried connecting the monitor on the other card, or using the DisplayPort?

 

That is a very cool looking build

Not a massive fan of the case but the internals look pretty special.

 

I doubt the distance between the cards are a problem... hm, and if you tried to wrap the bridge in aluminum already... I guess it would be the SLI bridge being the problem, I came across this thread on evga http://www.evga.com/forums/tm.aspx?m=744633&mpage=1 and if that is not the case... I would just say there is something wrong with the chips on the GPU. Hope it works out for you! I definitely love the passive cooling def a good inspiration for my next build if I do get to it

 

"Did you check the output and tried connecting the monitor on the other card, or using the DisplayPort?"

By default, the GTX570 on the right side is acting as master at this moment. When plugging the DVI-D into the left card, the monitor would not start up, even if I reset.

Is there a way (for ex. a driver or a bios setting) to make the one on the left side (the one under the risers, connected to the lower PCIe port) act as a master card without switching the cards and the risers? These risers are delicate so I would refrain from plugging, unplugging, bending them too many times, should it be not absolutely necessary to move them. I am going to check all the ports on those cards this way or another, it is just me asking if it is possible to soft-switch the master VGA?

Thanks!

jippa

Hanoken: Great link, I am getting into it. Thank you!
.//TuNdRa: Thanks for the microstutter clarification, I will somehow try the second GPU. As written above, my SLI does seem to care about which VGA is used, and simply would not start up with the one on the left hand side.

 

perhaps the sli connector is receiving interference? if it isnt, at that distance the signals in the wires could actually be interfering with each other. however minute the power at that distance... if all else fails(wrapping up that sli etc) perhaps make one yourself and wrap up each wire or twist them in pairs and wrap each pair...? only say cause they wouldn't not make that length without a good reason...

 

This project is a kick ass example of a passive cooling engineering! HR-02 on vids look baddass!


I think to debug your rig's SLI problem you need first to test your setup with a off the shelf SLI bridge, and with(and without) PCIe risers. If the problem sorts out to be custom SLI bridge dependent, then I think I know whats wrong. You see SLI signal is very similar to PCIe, and uses very high frequency signaling (GHz range maybe), at which DC impedance is not as near important as is wave impedance (or characteristic impedance @ given frequency), and other high frequency cable characteristics.

So measured DC impedance of SLI bridge may be OK, but at high frequencies it fails to transmit reliably.

So, to fix the problem you may need to make a new SLI bridge, using a high frequency cable, maybe a cat.6a ethernet cable, as it is certified to run at 500Mhz over a 100meters, or a Sata 6Gbps cable. But ethernet cable is twisted pair, and SLI bridge sim's to be a straight cable, so you may need to un-twist it, or if you can find SLI pinout you can use a twisted pair, connecting each cable pair to a corresponding transmit/ground (or transmit + and -) pins. Good luck!

 

Dear N!ck!

This is the second time I have been advised to use good quality ethernet cable to solder my own SLI bridge. I got this advice first in Hungarian forums. With you, time has come. Today, I bought some Cat.7 SFTP 900MHz cable. I will be doing it this weekend.

Good luck is what I'll need.

Best!

jippa

 

Custom SLI bridge from ethernet cable postponed to next weekend. After 8 hours of soldering, using category 7 (AWG23) 900mhz cable turned out to be a failure. It is too rigid, broke many tiny pins on the sli connector. Unfortunately.

 

Kudos to you for the effort. I honestly can't solder for more than an hour at a time. Mind wanders and I end up tweaking other things

 

Normally, it is an hour max for me, too. Except when you want something very hard.

 

BEST.BUILD.EVER.

 

still the effort will shine in the end, at least you have some clue to start with into fixing your SLI Problems, hope it works out for you bud

 

Sorry to hear that. But did you tested your setup with an of the shelf SLI bridge? Maybe the problem is some were else? Also try to contact nVidia support - maybe they will help.