i need a power supply and i found one thats SLI ready for like 34 bucks, 575w, pretty decent.. anyway, i have a crossfire card radeon 3870 hd 512 256 bit gddr4 (which is smokin! eats every game like a champ).. so is the whole sli/crossfire ready bs just a marketing scheme or is there really a difference? i mean, both have 2 pci-e 6 pins in them, whats the difference if i hook it up to nvidia or ati card? thanks!
I have a SLI PSU in one computer and a Crossfire PSU in a different one. The only real difference is the paint job and that the Crossfire one has a couple 8-pin plugs. One other thing, check out the tier listings for PSUs before anything is bought. Somehow I very much doubt that a good quality SLI ready PSU can be found for $35,
Usually if it has a thing saying SLI or Xfire certified it means ATI/AMD or Nvidia have tested the PSU with an SLI or Crossfire setup and concluded that it worked with stability. The problem being, it may say SLI certified, but if you go to Nvidias or ATI's sites to look at Xfire/SLI compatible PSU's it will be certified for an older dual card setup, not usually for whats out now.
But usually anything that says SLI/Xfire supported will be able to pull it. Just need to make sure there is enough current on the 12v rail/Rails, and enough pcie connectors. Think the 8pin pci e connectors are for the older ATI high end cards. My 3870 only needs 1 6pin connector.
SLI/Crossfire PSU's are pretty much the something, with the required connectors available from the PSU.
A $35 575W PSU is a ripoff, and a waste of money.
A quality, efficient, capable PSU in that range will run you $100.
Hit the PSU sticky and look at the PSU charts.
While SLI/CrossFire certification on power supplies and cases tends to be more marketing than anything else, I simply tend to purchase power supplies due to the level of comfort I feel with the manufacturer, and that is determined by PSU quality. Multi-rail power supplies for computers (and modular-cabled PSUs as well) have always left me feeling rather nervous. Any PSU that makes me nervous I would not buy (or recommend, because I won't recommend any product I won't buy myself). I read (earlier today) a comment regarding a recently-reviewed PSU (specifically, the new-design PCP&C Silencer 500 ATX/EPS), in which he castigated the Silencer from being an *overpriced Antec EarthWatts 500*. Having seen both PSUs (in fact, at the same B&M retailer), I'm going to point out two rather stark differences between the two:
1. While both were, in fact, sourced from the same OEM (Seasonic) and use the same caps, the EarthWatts remains (like all of Antec's 500W+ PSUs) a multi-rail design (dual 12V rails in the case of the EA500), while the Silencer 500 remains, like every PCP&C PSU, a single-rail design (one 12V rail supporting up to a 35A draw).
2. Contrary to being overpriced, the Silencer was actually priced less (by $24) than Antec's Basiq 500, which was $10 under the EA (EarthWatts) 500. (None of the three were on sale, and these were retail prices at the same retailer.) This is contrary to typical PCP&C pricing structure; the very fact that they could actually increase availability (especially retail availability) and lower the price without decreasing quality means that OCZ (in the acquisition) and Seasonic (the OEM) have obviously done something right.
For once, it's nice to be able to by a quality PSU without basically feeling that you have to BOHICA in paying for it.