Quick background: About six months ago I started picking up good deals piece by piece to build a box, taking my time and being patient for good value deals. I am down to only needing the video card, which is where the questions come in.
Current parts for build:
Intel i5 (intend to OC to 3.6-3.8)
WD Caviar Black 640
CoolerMaster 212 CPU fan
4Gb G.Skill PC3-15000 (1866) 9-9-9-24 (will probably run at 1600)
OCZ ModXStream Pro 600W PSU
The debate on the video card, which I intend to buy early next month, depending on sales, comes down to power and performance.
The power question stems from using a 600W PSU, vs a 750 (it was a pretty good deal on the PSU). The performance issue comes from value for the dollar and the issues with running Crossfire on Core i5.
Do I just stick with a single 5850 for around/just over $300, or do I run CrossFire or a single X2 card?
Single 5850 can easily work with the PSU. A 4850X2 on a single PCI slot might work, but I don't know if I want to step down to DDR3 memory on the card. And I don't know if I want to run 2 4870s in CrossFire because I don't know how it compares running them at 8x PCI-E vs a single 5850, and if my 600W PSU will handle it.
I just don't know enough about CrossFire and how much power I'm really going to need with this setup and I haven't seen comparisons directly between CrossFire at 8x vs higher-end cards in single slot.
If u can afford a single 5850 then grab it, no need to CF.
Your plan will be strong enough to play any games with high setting(mostly)...
A single card will produce less heat than two and of course less power consumption.
Go for a single 5850...Its a beast capable of running any current games at 1080p resolution and also dx11 capable...According to performance the gpus can be arranged as follows:
4870CF>5850>4850x2(settings tested using i7 extreme 965 and intel x58 mobo)
Also remember that CF scaling depends on both cpu and mobo...
THere are many drawbacks with 4870CF or 4850x2..
1.Cf scaling may not be good enough to outperform a 5850
2.4870Cf and 4850x2 both are apower hog...
4.No Dx11,majority of new games will use dx11
So it is sounding like, regardless of the mobo throttling to 8x, the 4870x2 will slightly outperform a single 5850 on pure horsepower (ignoring DirectX 11 and other minor variables), but the tradeoffs in power consumption and possibly heat make is a wash. From what I can see, there are no major market 4870X2 cards, so that doesn't play. And there seems to be no viable reason to go with 4850X2 or 4850CF vs a single 5850.
So with 8x throttling being such a minor concern, the follow up question is this:
I will go forward with planning on purchasing a single 5850, but if there were some ridiculous bargain where I could get two 4870s for under $250, it seems like the 4870 CF would be worth while, if and only if it wouldn't strain the PSU.
So, uhm. . . would it strain the PSU? I am fairly confident that a single 5850 would not in this rig, but correct me if I am wrong on that.
I have ran both Crossfired 4870's and 5770's. I find that my 5770's run and scaled much better than the 4870's. Plus the power draw on the 5770 is quite a bit lower than the 4870. I would not run a pair of 4870's on a power supply smaller than 750 - 800w. My ThermalTake ToughPower 750w some times choked on two 4870 1gb cards. I do agree with everyone else though a single 5850 might be most suitable for you. From what I understand is the i5 only does crossfire at 8x on both cards. Well I'm running my Crossfire set up on an ASUS M3A78-T, which only runs the slots at 8x in crossfire.
Yeah, you should be deciding between an HD5850 and 2 HD5770s. The HD4870, besides not having DX11 and using much more power, is getting both rare and expensive. Like everyone else I'd recommend the HD5850.
oooh, how did I forget about the 5770s? I could, in theory, grab one of those at a time over a couple of months to run in CrossFire. . . I could even justify spending the $200 now for the XXX version since it is still $100 bucks cheaper than a 5850 and then picking up a second in a couple of months for hopefully around $150 if nVidia's new cards give ATI some competition. . .
This is the problem with talking with geeks that know more than I do. I get a few answers and I'm like a kid in a candy store.
After a little more poking around on the forums here, I've decided to keep my eye out for a single 5850 deal or, if something really slick appears, a 5870. I have a month or so that I'm willing to wait for a best deal. Hopefully nVidia comes out with their new cards soon and will drive some prices down.