Why not? you could hey a sli mobo and get a good card now, then later one get
that same card and it'll be cheaper then buying a good card in the future
Hmmm since neither of us have time machines (i had one but lost it when i put it into the infinite acceleration cylinder) Lets have a look at some price trends shall we?
Last Generation
First lets look at the 6800Ultra, flag card of the last generation
We have a launch price of roughly $480 and after a six month periof we have a price of $510, an decrease of -$30. This would mean that the cost of two 6800Ultras over six months would be 480+510 = 990USD
Lets have a look at a different card, say the more popular 6800GT
Looks like we've got a launch price of $350 and after six months, a price of roughly $380. This gives us a SLI price of $350+$380 =$730
And lastly, lets have a look at the popular midrange card, the 6600GT
Here we've got a launch price of roughly $180 and a stabilized price of roughly $145 which gives us a SLI price of $325
Current Generation
Now lets look at current generation hardware, first the 7800GT
Looks like a price range of about $300
Now the 7800GTX, we have a NOW price of $468 and looking at the trend (using the same pricing engine to rule out bias)
We've got a current price of about $460
Now just for kicks, lets have a look at the 7800GTX/512,
Looks like a rough price number of $700
Now let's tabulate
66GT-SLI = $325
68GT-SLI = $730
68U-SLI = $990
66GT followed by 78GT = $180 + $300 = $480
68GT followed by 78GTX = $350 + $460 = $810
68U followed by 78GTX/512 = $480+$700 = $1180
Savings from SLI for 66GT = $155
Savings from SLI for 68GT = $80
Savings from SLI for 68U = $190
Digging Deeper - Quantitative
So it seems that it would be cheaper to get the SLI route but lets dig a bit deeper. First let's look at a very popular NF4Ultra board, the DFI LanParty UT NF4 Ultra-D
Looks like an overall ballpark cost of $120
Looking to the bigger brother, the DFI LanParty UT NF4 SLI-DR (since the Expert wasnt available 6 months ago),
So we've got a ballpark price of $165
So updating the savings,
Savings from SLI for 66GT = $110
Savings from SLI for 68GT = $35
Savings from SLI for 68U = $145
And A Bit Deeper - Qualitative
- For the first scenario, 66GT vs 78GT, we can qualitatively rule out any advantage to the 6600GT-SLI solutioin: the 7800GT is, from a technical perspective, superior. We can also probably do the same for the 6800U-SLI vs 7800GTX/512.
- Not considered was also the resale price for the cards in a non-SLI scenario -- which is more than enough to quantitatively account for any advantage SLI might have
- The only odd case is the 6800GT-SLI vs 7800GTX but in this case, even a disadvantage of $35 (or $80) is hardly significant over 6-months as well as (in the case of the $80 disadvantage) the potential to have 2x78GTX
