Whether to go in for a multi-GPU setup or a single powerful graphics card is quite arguable. But it will all become very clear to you by the time you reach the end of this page. Before we delve into the topic let’s start with the basics of SLI and CrossFire X.
Scalable Link Interface or SLI is Nvidia’s multi-GPU technology that allows clubbing the power of two or three graphics cards by linking them together on the same motherboard. CrossFire X is ATI’s technology and does the same job, the difference being you can club up to four graphics cards on a single PC. The hardware requirements of SLI and CrossFire X also differ. First of all, you require a motherboard that is either CrossFire X or SLI-compatible.
There aren’t many SLI motherboards to choose from, and the ones available are high-end and expensive. Whereas, there are plenty of CrossFire X motherboards available in the market, such as the ones based on AMD 780 GX, 790 GX and 790 FX. Secondly, you require two or three identical Nvidia graphics cards to configure them in SLI (same GPU and amount of video memory). In case of CrossFire X, you can club two or more cards from the same family as well - for example, Radeon HD 4850 and HD 4870, which belong to the HD 4800 family.
Starting from Rs. 3,500 you’ll find a more powerful graphics card at every Rs. 1,000 interval, way up to Rs. 35,000. You will easily find a single powerful card that will be equally powerful as two mainstream or mid-range cards. In some cases two cards in SLI or CrossFire are more powerful and budget-friendly than a single powerful card.
We tested a few SLI and CrossFire setups to show you how powerful they are as compared to single high-end cards. Two GeForce 9600 GT graphics cards (each costing Rs. 5,500) configured in SLI perform equally well as a single GeForce GTX 260 which doesn’t cost less than Rs. 13,000. Next, we clubbed two GTS 250 graphics cards (each costing Rs. 10,000) and found that their combined power easily outperforms a single GTX 285 which costs around Rs. 26,000 - a saving of Rs. 6,000 if you opt for the former! We also jammed two Radeon HD 4770 graphics cards in CrossFire and found that a single Radeon HD 4890 a much better deal. Both the options cost the same (around Rs. 18,000), but a single graphics card is more preferable.
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These are just a few examples. There are many more such smart multi-GPU setups that are great value for money. But at the same time a single powerful graphics card can be a better option than two mainstream cards. It will be lighter on the power supply and at the same time the heat dissipated and cable clutter will be less. There are many who hesitate going in for a multi-GPU setup because compatible motherboards are priced steeply and the cost of ownership is high. You also require a cabinet with good cooling because the amount of heat dissipated by two cards is much more than a single card.
However, if you already have an SLI or CrossFire motherboard and a good power supply, it makes a lot of sense to add another identical card (especially if it’s a GeForce 9600 GT) if you want to upgrade your graphics card. Multi-GPU is the way to go even if you don’t have a budget for two powerful graphics cards. So, you invest in one card today and add another card some time later.