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SLI Primer
GFXguy writes "If you are looking to catch up on some hardware learning you may want to check out "SL Why?". It is a short article that goes over the basics of SLI graphics. The article goes over some strengths and weaknesses of this technology as well. It looks like one video card is not going to cut it any more, at least for the hardcore gamers out there. "
SLI is overkill for 99.99% of people out there. In fact, onboard video is fine for probably 80-90% of the PC market.
You see? You see? Your stupid minds! Stupid! Stupid!
What about those of us who want to spend a sane amount of money on their computers? Gamers are getting almost as bad as audiophiles these days.
It doesn't matter how hardcore a gamer is, if they can't afford 2 uber-graphics cards, they're not going to buy 2. I own one Geforce 6800 GT, and it doesn't seem to have problems in any game I play. As long as frame rate >= refresh rate, it doesn't matter anyway. Instead of buying an elite SLI system now, I saved that money... in a year or so, prices will fall and I'll be able to buy a new motherboard AND top of the line graphics card instead of having an old system with 2 obsolete cards.
I don't understand why anyone except a small group of enthusiasts would still play PC games. Sure, there's a better interface and higher resolution. But, game installation is generally a true pain - install the game, update the drivers, download the patches, fiddle with the game options, rinse, repeat. Then there's the constant need to install new upgraded hardware (like a new $250 video card) to play tne next version of a game.
Contrast with purchasing a console, hooking it up to the TV, popping in the game and playing. New hardware (consoles) appear periodically (like XBox2, PS/3) but upgrade cycle is a lot less frequent than that required for PC games, and hassle factor is much lower. Add to that the fact that most game makers now develop for consoles first, and it's hard to justify the continual upgrade cycle to support PC gaming.
[Insert pithy quote here]
#1) Doom 3 runs in SFR mode, not AFR.
#2) CPU issue is overblown. I'm not even sure if any additional information is truly sent to the processor.
In AFR, the data for each frame is sent to alternating graphics cards. Since the frames would have been processed anyway, there is not any additional load on the CPU than there would be for an identical system with a video card that is twice as powerful as in an SLI system.
In SFR, the same data is sent to two graphics cards. This would be more data, but seemingly require only a smidgen more CPU power. The video cards send the data between each other over a dedicated bridge, and the video cards handle the task of reassembling the image into a single frame.
#3) SLI card cost. 6600GT AGP cards cost more than their PCIe counterpart. 6800 AGP cards cost less. This has more to do with the amount of time in the market than anything else. In 3 months, the prices will be equal.
#4) Stability. "...certain older cards that are said to be SLI compatible have serious stability problems when used with SLI, but, for example, not all 6800 GT cards can be used with SLI". To date, I have not seen a PCIe 6600GT or 6800GT card released which is not SLI compatible. Not all 6800GT cards can be used with SLI, but that has more to do with the fact that many cards are AGP based and older than two months (when the first SLI motherboards were released).
#5) No benefit. "From what I heard, more than a few games realize no FPS gains at all from the addition of a second video card". First, this is rumor. Many games realize no benefit at low resolutions (640x480, some at 800x600) because the games are more CPU bound than video card bound. All the games that are SLI compatible definitely realize solid FPS gains. Moreover, those gains can be "converted" into graphics enhancements (i.e. no need to go from 60fps to 95 fps, but now you can turn on 8xAA or up the screen resolution, etc.)
#6) Dual GPU cards. The author obviously doesn't know what he's talking about here. The Gigabyte dual GPU card is just an SLI solution on a single graphics card. It's (almost) exactly the same as having 2x6600GT cards. It uses the same technology and produces the same results. So what's this viable new technology on the horizon he is talking about?
#7) SLI cannot be forced. Of course it can! The default mode is "no SLI". This can be changed in the configuration options for the card.
Actually with a lot of games using seamless worlds these days, there is a lot of read/write activity in game. This creates noticible slowdowns (play World of Warcraft and try running through Ironforge.. lots of HD activity before it loads all the character models/textures/etc.) I actually have a RAID 0 myself, and it does speed things up a bit. Of course, your money is probably better spent on CPU, video and RAM.
I just upgraded my computer after having the same one for 4 years... which as a CS major (well, I just graduated) is a pretty long time. How do I make my computer stretch so far? Buy upgradeable solutions up front... and that's exactly what I did this time.
I bought an SLI mobo (MSI K8N Platinum SLI)... put the slowest 939 pin Athlon64 I could find (3500+) (the price ramps up significantly passed this point).... then I bought _ONE_ Geforce6800 GT and 1GB of RAM in two sticks (leaving two slots open)... and finally a 535 watt SLI power supply.... Then hooked it all up to a new 19" Flat Panel.
All in all I paid about $1600... which is a little bit but let's look at the upgradeability.
First of all there's the obvious SLI slot. In about a year when 6800GT's are $150... I'll be able to nearly DOUBLE my performance in games. That's a pretty good upgrade.
I left two RAM slots open so I can jam another set of 1GB sticks in there in a year and have 3GB.
The newly announced dual core chips from AMD will work in my current 939 socket... with a BIOS upgrade... so I will be able to again almost DOUBLE my CPU performance (blah threads, blah, I do a lot of compiling and stuff so it will be a big upgrade for me)
So there you have it. I didn't spend a million dollars... but my computer is REALLY future proof. I probably won't do another $1500 upgrade until about 3 to 4 years from now... and like I mentioned I'm a fairly heavy computer user.
So for me SLI is future proofing my system, and I, for one, am grateful!
Friedmud
The technology has changed. While the Voodoo cards used to simply draw every other line on the screen when they were SLI'ed together, today's cards work very differently.
In a nutshell, one SLI'ed card will (attempt) to draw the top half of the screen while the other card draws the bottom half. Now, there are exceptions to this, and this is the biggest change.
If say, the top half of the screen does not have as high a polycount as the bottom half the underperforming card will pick up some of the slack for the over-worked card drawing the bottom half. This results in the cards working together to acheive an optimal frame rate.
For more detailed information than my bland attempt to sound geeky, click here.
I agree - audiophiles are worse, INITIALLY. But they can usually resell a piece they replace (sometimes at a profit). Us gamers buy a $500 card to trash it 6 months later.
My stereo will clearly play great audio long after I trash my current rig, and a few components after that, too. Until you can purchase an ear upgrade, anyway. The next FPS down the pike will make my PC a paperweight...
Face it, do something enough times, and it can cause problems.
Points taken, but a 5 year old amp will stll have market value and play music just as well as the day it was made (assuming the amp is a quality product to start with), while a 5 year old videocard simply will not.
Face it, do something enough times, and it can cause problems.
This may be one of the worst SLI articles I have read so far. This guy makes assumptions and passes them off as fact. He also makes some statements that belie his lack of knowledge about systems and speeds of procs as well as potential bottlenecks in the system. While SLI may be a good idea in the long run currently it is just a very expensive toy for certian gamers to brag about. Actual performance increases have been around 30% in most of the tests I have seen so far. That extra $200(6600gt) to 380(6800gt) spent on the 2nd video card combined with the extra $100 you will have to spend on the motherboard is better invested in other places on the system. upgradeing to a almost top amd64 or gasp a p4 will in the end get you better speeds in the majority of games. For sli functionality the driver has to support the game, and so far few games have been selected by nvidia to have the drivers writtin for it.
SLI does have some potential advantages that this writer has not covered. In 3d rendering, real time editing or special effects work this type of setup would be a huge boost to speed and productity. The fact that this generation of cards have programmable shaders, means that in theory these cards can pull some processing functions off of the cpu. Currently people are starting to experiment on how to use these powerfull graphic cards as almost secondary cpu's.
Currently my amd 64 3200 with a 6800gt performs amazingly in doom III and HLII at large resolutions with AA and AF. Ironically esp in HLII the bottleneck is the processor as the game has to compute the large physics calcs demanded by HLII. WIth graphics getting as advanced as they are I think we will be seeing a return to proc based performance gains, and a slow down of video card performance increases. As games will be putting more of a draw on the CPU. The graphics are real, now the environment is getting real.
Personally I feel that SLI is very much like the P4EE an incredibly expensive add-on/upgrade for very very high end gamers that do not care about price, or are easily swayed by marketing. At this point SLI makes no sense. The power is not needed at this point, the price performance ratio is way out of skew, and it's future is in doubt. Nvidia has to supply the drivers for these games, and as far as I know no games are currently being written with SLI in mind. Lets check back in a year and see how it goes and where this tech has gone. And as a parting thought why has nvidia not started using this tech in the commerical sector????
---In a time of Chimpanzees I was a Monkey.