Quad GPU explained
The Quad GPU experience - What's that?
As most of you know both ATI and NVIDIA have solutions on the market called Crossfire(X) and SLI. Basically this will allow you to play your games with the help of multiple graphics processors (GPUs). Within the confines of compatible mainboards you can increase the overall rendering performance of your games and thus increase your graphical gaming experience in several ways. Simply stated, you can run two or more "graphics cards" on selected mainboards, or better yet one (or more) graphics card(s) with multiple graphics cores on it.
Utilizing more of them, whether that is two or more GPU's on a videocard or two graphics cards in one system, is what we call Multi-GPU processing of games. And that was our focus, to simply look at the most competitive multi-GPU solutions available on today's market and to see how they perform and functions. Quad SLI/Crossfire obviously simply means that there are four GPUs (graphics chips) being utilized for your gaming experience.
Power Consumption
It's impossible for me to leave this topic untouched, power consumption. What we are showing today is far from healthy. A high-end system is required for Quad-GPU gaming. Meaning with today's tested gear, we recommend a move towards Core i7. Next to being expensive, it's also a power hungry platform. Add to that the two GeForce GTX 295 or Radeon HD 4870 X2 cards with 4 GPUs per setup and you can understand that power consumption can and will go into the stratosphere. Mother nature will not be happy.
It's good & bad though. Compared to two years ago when we tested the first 2-way and 3-way SLI/Crossfire systems, overall power consumption for Multi-GPU setups hasn't changed a whole lot. Despite that "level" of power consumption, performance has however went up tremendously. The industry is very much aware of getting the most computational power per watt out of each GPU.
I remember when we tested for example the 9800 GX2 in Quad SLI. That system consumed roughly 700 Watt when it was peaking.
The good news, that number is still the same. The bad news, of course it is way too much.
Though SLI / CrossfireX is real fun and a very fast way to quickly get more performance, but as stated it also effectively adds more 'load' on your power bill. Each 4870 X2 or GTX 295 card can consume up-to roughly 300 Watts per card if the card is 100% stressed.
We'll now show you a bunch of tests we have done on overall power consumption of the PC. Looking at it from a performance versus wattage point of view.
The methodology is simple: We have a device constantly monitoring the power draw from the PC. After we have done all our tests and benchmarks we look at the recorded maximum peak; and that's the bulls-eye you need to observe as the power peak is extremely important. Bear in mind that you are not looking at the power consumption of the graphics card, but the consumption of the entire PC, measured from the power draw at the wall-socket.
Note: Our test-platform is based on a Core i7 965 / X58 / 6 GB based and overclocked to 3.75 GHz. Next to that we have energy saving functions disabled for this motherboard and processor (to ensure consistent benchmark results).
Our ASUS motherboard also allows adding power phases for stability, which we enabled as well. I'd say on average we are using roughly 50 to 100 Watts more than a standard PC due to these settings and then add the CPU overclock. Keep that in mind. Our normal system power consumption is much higher than your average system.
Videocard |
System Under load |
GeForce GTX 295 QUAD |
712 Watt |
HD 4870 CrossfireX QUAD | 730 Watt |
It's tragedy to see one PC suck up as much power as you can see above. So remember if you'd even opt Quad SLI or Quad CrossfireX you'll be using an incredible amount current ... no doubt about that.
It's not 'just' about the graphics cards
We are talking about über-über top level game rendering here today. There might be an audience of like 0.001% out there actually buy this, as your system has to be right in many ways, and I'm not talking about the stack load of money you actually need to make all this happen. Let me give you the more important pointers.
Here's what you also need to think about when building a Quad SLI / CrossfireX rig component's wise and also why.
Say it out loud ... I'm broke, yet I'm proud !
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Mind you that you'll also need Windows Vista to get Quad SLI support. Windows XP does not support more than 2 GPUs properly.
That's right, you need a huge budget. All these components are high-end and thus performance is at top-level. Especially four GPU's in one system will be an issue when it comes to heat. The videocards will dump huge amounts of heat into your PC. So PLEASE get yourself a high-end casing in the likings of Lian-Li, Coolermaster Cosmos S, Thermaltake Armor+ -- just make damn sure it's well ventilated.