Area 51 ALX Replacement graphics cards

HD5970 is a 294watt card / R9 390 is a 275w card; since you had dual-5970's your psu 'should' power dual-390's, so long as you have the 1100 or 1200w model & you follow the connecting scheme stated in the flow-chart. My photo of dual-5970's in tandem with the 1100w model is the proper connecting scheme for dual-cards, where the black cable represents each card is getting one half of a 12v rail, (lol), while the blu & ylw are whole rails. The 1200w would differ in that one cable coming from the chassis & one cable coming 'from out of the harness' is used per card, for instance one white & one blue for the top card, both yellows for the bottom card etc. I mention this due to your angst that cross-fire is in jeopardy; maybe yes maybe no, depends on the health of your psu after all these years I would imagine. I sell power supply swap kits for Area-51; think it over while I still offer them.

I had 2xHD5970 in my area 51 alx machine, one stopped working so decided to get R9 390 G1 gaming card from gigabyte which works splendidly until the graphics are pushed (fan kicks in) when the whole system suddenly shuts down and restarts.  I have the 6+2 and 6 pin plugs which fed one of the old cards feeding the new card.  When you say you had to 'spilt the power cables that fed the old two card set up so that one is feeding the 8 pin socket and another is feeding the 6 pin socke' do you mean you took the six that fed one of the earlier cards and the 8 that fed the other.  Could using the power connectors from a single set of cables be why my machine shuts down, i.e. overloading the PSU from one cable ?  If so, I guess that scuppers plans to crossfire 2 cards :-(  I am also a little surprised that the PSU won't take the new card alone :-(

This owner (Alienware Area-51 PSU?) claimed success; R9 390 paired to the 1200w psu

eventually the separate white & yellow cables were used (i.e. powered by two 12v rails)

EVGA powerboost was on his shop list as well ...

Better late than never :-)  Do you think it fails because only one card is drawing power from one of the two rails i.e. could it be shutting down because the power drain is unbalanced ?  So, if I put in two cards, each taking power from a seperate power rail, would it be expected to work properley ? (I hope that makes sense)

let's look at Aurora, which only got two cables

blu-wht & blu-ylw

525watt power supply? only one cable 'works', Is 'live' >< 875watt: both cables work

• for 875w, each cable is on its own dedicated independent 12volt rail
• like Area-51, each 12v rail is rated at 18amps = 216watts
• each 12v rail is 'circuit breaker protected', psu shuts off if load exceeds 18amps
• each cable consists of a 6pin + jumper 6+2

in a low power situation, one cable is being used & one cable sits unused 

card has access to 216watts | card has lost access to an additional 216watts

for best results, the single card above should be using both cables

if the card above wished to draw the entire 215watts? PSU would be on the brink of shutting down. But if each cable were deployed? Each cable would shoulder 107.5 watts & greater. No longer one cable handling all 215w, the psu rails won't heat up as much if / when shouldering only half the burden etc, power supply doesn't have to work so hard pumping juice over just one cable 

whether this is a low or high power card above: it now has access to the full 432watts (216w x 2)

in SLI X-Fire, Aurora is limited by the type of cards it can power, restricted to only those cards which will not draw more than 216watts over one 12v rail. We might expect the PSU to shut off anywhere from 18amps - 19amps. Aurora was limited to the types of cards it could run, due to only two cables

even if this card is 'ok' using the blu/wht primary + blu/wht 2ndary jumper, things go better for card & psu when blu/wht & blu/ylw - when both 12volt rails - are deployed & engaged

Area-51 1kW & 1.1kW

• 1000w has two cables | two 12v rails
• 1100w has three cables | three 12v rails

Area-51 1.2kW J297R & VHM5V

• J297R has four cables | four 12v rails

VHM5V has four cables | one 12v rail rated at 46amps

Both 1200w models have a pair of cables wired internal to the chassis (white + yellow), while the other two video cables come from the case harness (blu + yellow)

above is one of the very last Area-51s, with a December 2011 build/ship date, & a rare one at that, ordered with dual GTX 590, which are hungry cards indeed. This owner is using VHM5V, & the cards have access to 46amps or 552watts over the four video cables. We expect the power supply to shut off when the load reaches 46- 48amps. VHM5V is a revision to J297R, it was made special to handle GTX 590s HD 6990s & triple HD 6950

whereas the 1kW &1.1kW models had definite 18amp rails, J297R has four 12amp rails, such that when some magic combination of load occurs between 12amps - 18amps over any given cable | 12v rail, the psu shuts off. VHM5V 'cured' this by making one large 12v rail, or, combing all four of J297Rs into 'one large rail'.

whether this is the 1kW 1.1kW or J297R, it's two connectors, yes, but only on one cable

regardless

the 1kW model can not be expected to run dual-cards of any import

if you have the 1.2kW model, refer to the GTX 590 photo & use all four cables

if shutdown occurs, try an EVGA Powerboost PCI-express lane 12v power augment

if shutdown occurs? see my power supply swap cables for help with MIO board

these were made & shipped last week for a Corsair psu swap

dual 294watt HD5970

• 1100w has three cables ylw blu blk
• each cable wears two connector pairs
• black cable only has 6pins
• 1100watt needs help for cards needing dual-8pin power, due to black cable 6pin pair

example: top card gets one ylw cable, rated at 18amp | 216watts, & 'shares' the 18a|216w black cable

• top card now has access to 216w + 108w = 324w
• bottom card has access to 324w also
• these are ideal figures: shutdown may occur before cards broach 648watts over three rails

with ONE card paired to the 1100watt, cables to choose are the ylw & blu

the lesson here: always deploy two cables | two rails per card for best performance

So, if I put in two cards, each taking power from a separate power rail, would it be expected to work properly?

To work properly, the power requirements of the cards can not exceed the rated power output of the power supply.

above are connector charts for all validated cards

highest power cards offered were GTX 590 / 690 & HD 5970 / 6990

to have a feel for what today's cards can do compared to whatever psu model you have, research the power needs of the older cards above, then extrapolate your chances of running that new card