synthesis204

Hello all,

Computer specs are the rig I am talking about; I'm looking into adding a second GTX 460 for SLI in my computer, but am concerned about the motherboard spacing.

Currently, it looks like there would be literally no room between the two cards (putting them in the X16 lanes) - about less than a centimeter. Anyone familiar with SLI or this specific motherboard - can you alleviate my fears? Do two SLI'd cards with such little room in between overheat or run fine? Would I be better off selling my current 460 and picking up a 5870/480?

Thanks!

Tipstaff

The top most card will be pulling air from the backside of the bottom card, so it won't be getting fresh/cooler air. I've never had a card overheat due to this though, just have slightly higher temps than the other card. In fact the bottom card will be slightly cooler since the top card is pulling heat away from it.

Performance wise 2 x GTX460s are faster than both a GTx 480 and an HD5870. If you want performance of SLI/Crossfire I would instead go with the HD5970. Just be aware that this card is very loooong (1 to 1 1/2 inches longer than the HD5870... about a foot long), but thankfully the power connectors are on the top of the board, and not the side.

Here's something to note about that board. The PCIe speed setup is normally either 16x8x8, or 16x16x1. So, if you only use the 2 blue slots you will get 16x16x1 (both cards run at full lane speed). If you do Tri SLI or Crossfire X, the lanes will be 16x8x8 (first card runs full speed, 2nd and 3rd at 1/2). This happens automatically by default, however, in the bios under Advanced | North Bridge Chipset Configuration, you can manually change the PCIe Express Selector to for slot 2 and 3 to 8x8, or 16x1 (first slot will always be 16x). What this means is that you could use the very last PCIe slot for SLI, but you'd have to get a very long SLI adapter to bridge the cards AND the last card would only run at 8x. That would alleviate your heat concerns, but you'd need a case that has space at the bottom of the board for this to work (either that, or remove the PSU, and make it external.. LOL!).

__________________

synthesis204

I was aware of the lane specs, but hadn't thought about the cooling part of it. If I have one reference-cooled card and one aftermarket cooled, would you recommend the top card (pulling air away from the latter) be the aftermarket or stock? I would think to put the stock beneath and the better-cooled one on top, but to each his own?

And yeah - is it possible to have it run at x16 x16 x1 with 3 graphics cards? I have a 9500 GT PhysX card in the last slot right now, but would prefer to have it run at x1 over x8 since its only used for PhysX/my third monitor (nVidia's 3 monitor set up in a pita).

And I'm aware a 460 SLI beats both the 5870 and 480, but not by a terribly large margin, and given space requirements, I would prefer one card over two.

CJLMTLCA

Triple card will run x16 x8 x8

My first 5870 idles 10C warmer than the second. But i have Vapor-Xs, so they are already pretty cool. I don't feel like blocking all the stuff at the bottom of my mobo, otherwise i would move it to the third slot and run x16 x8

__________________

Tipstaff

In turn:

Either way you look at it, stock or aftermarket, both will take up 2 slots unless you go with water cooling. However, you may find some aftermarket coolers taking up more than 2 slots. For instance, the Gelid Icy Vision takes up just under 2 1/3 to 2 1/2 slots thanks to the fans. So, if you use that particular cooler it'll have to be on the bottom card.

Edit: I just realized that if you use the 9500GT you may not be able to use the Gelid at all since the spacing is the same for all the slots.

As for the slots, I've never run an SLI setup with a PhysX dedicated board to know if it will auto switch 16x16x1, so you may have to over-ride the settings in the bios to get them to run that way (in this case choose the 16x1 setting).

I'm in the same boat as you. I once had a Crossfire setup, and it was the worst decision I ever made. It's one thing to run SLI/Crossfire on higher end boards, but trying to get high end performance by running 2 lower end cards... not worth it. Not that it didn't work (sometimes it actually didn't because a few games wouldn't work in Crossfire), but the heat vs noise vs power drain just wasn't worth the performance gain. After that disaster I went back to the single card routine.

__________________

synthesis204

Yeah. The 460 aren't exactly low end (more mid-range) but the SLI scaling on them is amazing, which is why I'm looking into an SLI over just an upgrade. I think I may wait till November to see if 460 prices drop anymore, or if NV releases a full gf104 rather than a limited version like the 460 - may upgrade to that, instead. If there isn't a full gf104 card by the end of November and the 460 prices haven't dropped too much, I'll probably end up going with a Powercolor PCS+ 5870.