The deal on MxO and SLI
Tested config:
Hardware:
-Asus A8N-SLI Deluxe (nVidia certified SLI compatible mobo)
-AMD Athlon 64 FX-55
-Dual eVGA 256-P2-N377-AX 6800u (nVidia certified SLI compatible vid cards)
-Creative Labs SoundBlaster Audigy 4 Pro
-2G RAM Corsair XMS running dual channel, of course. 4x512M.
-PC Power and Cooling Turbo-Cool® 510 SLI (510ATX-PFC) (nVidia certified SLI compatible power supply)
-4x74G Raptors. Running 2 RAID 0's. 2G page file on each logical drive.
-Adaptec 2410SA RAID controller.
Soft/Firmware:
-DirectX 9.0c
-Mobo BIOS Rev 1.006
-nVidia Forceware 71.84 (CoolBits Enabled)
-nVidia nForce 6.53
-Windows XP Pro SP2, all updates.
-Executive Software Diskkeeper 9.0, boot time defrag of MFT, swap files and directories + regular full defrag of sys.
Does it work? Sort of. Lots of problems.
1. The system has no clue which card is the primary card, so when first enabling SLI you HAVE to have 2 monitors. You can't enable SLI without it... because if you just switch the monitor to the other card, the nVidia drivers generate an error saying that your monitor is plugged into the secondary card. If you switch it back, it still thinks its plugged into the secondary card. Es tres stupide. [edit: Current beta drivers (71.89) no longer care which card your monitor is hooked up to... thank goodness. -R]
2. You have to start MxO with SLI disabled and then set what resolution you want it to run at, otherwise the game will render full screen, but your HUD will render at 800x600. While it's fun to see the entire compass (haha) it also means that your mouse can only interact with things within that 800x600 box.
3. The loading dock is a pain in the ass with SLI. It always renders in the upper left corner of the screen (no matter what monitor scaling is set to). This wouldn't be a big deal except that the dialogue boxes are centered on the screen, and since the game is only rendering the upper left corner, you can't interact with dialogue boxes above about 1600x1200 resolution. Also, the chat box is off the screen, so no chat for you in the dock! [edit: This only happens after jacking in. On initial client start-up, the dialogue boxes and chat window work just dandy. -R]
4. It is impossible to run a digital monitor at anything other than its native resolution. Which might be a contributing issue to the above problems. [edit: Yet another reason to never buy anything apple. -R]
5. Heat. With the introduction of the geForce 6 boards, nVidia rewrote its cooling spec in a stupid way. The cards blow waste heat into the case. The geForce 5 boards blew it out the back of the case and actually managed to justify taking up two slots. The ASUS board has its nForce 4 SLI chipset right next to one of the 6800u's which lends to more problems. Basically there's too many cooling systems all blowing against each other instead of all blowing the same way. Liquid cooling might be neccesary because of airflow issues. The other option is a blow hole in the side of the case blowing out, thereby helping to remove heat from the cards and the chipset. I've got a fatty heat pipe over the proc and mem, so that's all kinds of disco.
6. Power. The
510 barely cuts it with 5 drives. I'm thinking about upgrading to an
850 with the EATX connectors - though it would need a custom wiring harness with extra length cables - which pcp&c has always been happy to do. (Mobo has an EATX power connector but an ATX 12V connector - EATX 12V is 8pin, ATX is 4pin. O_o The case also mounts the mobo upside down so proc is at bottom - for the heat pipe... but means cables need extra length.)
7. RAID. The nVidia RAID controller is the biggest piece of shit and waste of system resources ever. Bless ASUS for including an SI controller as well. [edit: Having popped in a beta BIOS and beta nVidia RAID drivers to see if that helps, I've found that I want to amend my previous statement with a lot more expletives. -R]
8. Price versus Performance in MxO. Baseline - (1920x1200,high ram, high perfomance,antialiasing enabled) Dell with a p4 3.4/6800u/2G RAM avg FPS in MxO: 15fps. SLI rig - avg FPS: 25fps The biggest advantage is in particle effects and loading time. The 512M of video memory on the two boards seems to make a huge difference in load time [edit: It ain't the memory -R], and spamming group upgrades and concealment countermeasures in Mara doesn't even make the SLI rig twitch. Smooth as silk. Which is nice.
9. PCIe 8. The two PCIe16 slots share a PCIe16 bus, so they're both only running PCIe8. No big deal. Nothing to date has even stressed an AGP8x pipe. Processors just can't throw triangles fast enough yet... The only concievable issue would be with importing video - since that's the current advantage of PCIe over AGP. PCIe has as fat an upstream pipe as its downstream pipe, whereas AGP's upstream pipe is always AGP1x regardless of what its downstream (AGP1x/2x/4x/8x) is rated at. Also, the cards are capable of throwing data back and forth from vid memory over the SLI connector without using the bus... so yeah. No hit on rendering speed.
Summary:
Is an SLI rig just for MxO worth it? No.
Is an SLI rig worth it for people who aren't used to dealing with highly unstable systems that might need reconfiguration everytime it crashes? No.
Is it worth it for playing FPS (if you have the cash laying around)? Oh yeah. My teeth are bleeding. Clear into stupid levels of speed on Source based games (170fps with 16x aniso, 6x FSAA, 1920x1200 res, true trilinear filtering, all settings max). (Like back in the day running a Orchid Righteous 3D - 4 3dfx voodoo procs on one board - and Dark Forces 2: Jedi Knight.) Republic Commando is also super sexy on SLI. Thief: Deadly Shadows is gorgeous.
Reason not to buy SLI: You have a DVI only widescreen (like an apple display) that you aren't willing to part with. The native resolution only thing is a nightmare and timing can not be adjusted... so... get ready for a flicker fest! DVI and SLI hate each other, but can be made to work with limited success if a monitor has an analog input as well. For some reason, timing can be adjusted on an analog input and carry over to the digital input... But really. It's just less of a hassle to run it on analog when running with SLI enabled.