Dual 5770 - Power Supply?

[Borman]

Just curious if Im going to need an external power supply for this setup, in a Mac Pro 1,1. Thanks.

 

[fouel]

5770 Just have one 6 pin power cable

Just curious if Im going to need an external power supply for this setup, in a Mac Pro 1,1. Thanks.

5770 just has one 6 pin power connector.
Mac pro 1,1 has two 6 pin power supply.
It is sure that you can plug in two 5770 in your mac pro 1,1.

 

[Borman]

I know, Ive got one. I just want to make sure theres enough power from the power supply itself. Probably going to pick up a Windows-only one though to go with my mac version, no need for 2 in OSX.

 

[nanofrog]

You won't need an additional PSU for running a pair of 5770's. You will however need to use Apple's graphics card cable (can get them here), as the end that plugs into the logic board is smaller than the standard end that goes into the card (PSIG standard).

At least one member used a 6 pin PSIG Y splitter, but I'm hesitant to recommend this, due to the current draw (power is transferred over PCB traces on the logic board, and could melt the HAL and short <HAL = Hot Air Leveling = layer of solder on the traces> - seen this before).

Given the cost of the cable you need ($3.95 & free shipping), it's not worth the risk IMO.

BTW, if you're buying the card from Apple, the cable will be included.

Hope this helps.

 

[Borman]

That helps a ton, thanks I knew I'd need another cable, but hadn't seen that site. I was figuring I'd have to pay a lot more. And yep Ive already got one Apple card in there with the cable, so I know how that goes. Windows cards that only require the one 6 pin should be the same cable, and not yet another proprietary connection, right? Thanks again!

 

[nanofrog]

That helps a ton, thanks I knew I'd need another cable, but hadn't seen that site. I was figuring I'd have to pay a lot more. And yep Ive already got one Apple card in there with the cable, so I know how that goes. Windows cards that only require the one 6 pin should be the same cable, and not yet another proprietary connection, right? Thanks again!

The connectors on the 5770 are the same (standard 6 pin PSIG), whether you bought it from Apple or another vendor (PC versions will need to be flashed to work under OS X BTW, as they contain BIOS rather than EFI or EBC = needed to boot in a Mac).

But you'll only need to buy this cable if you use a PC version.

If you do decide to go this route, there's resources in here on flashing non-Apple branded cards (needs to be supported by OS X in terms of drivers), but netkas.org is where most of it originated.

You may also want to note that Crossfire or SLI won't work under a Mac as-is under Windows, or under OS X at all (seem to recall a hack or two that may allow this under Windows - not sure what card model restrictions may apply, so this would also require some research). The reason for this, is I'm not sure if you're into Windows gaming or not (or where you're sourcing the second 5770 from).

Hope this clears things up.

 

[Borman]

Gotcha. Cable is on the way, card should be here next week. I don't need it to work in OSX so its a non-issue, nor is crossfire necessary right now, but I know I can figure that out when it comes time. Thanks for your help, everythings all cleared up now. Crossfire should work fine anyway, I think its SLI that has the issues and needs more hacks

https://forums.macrumors.com/threads/989910/

There may be a small chance of needing to hack something up, but it should be fine.

 

[Borman]

Just reporting that it works mostly fine. Only downside is that in Windows, old drivers are necessary to enable Crossfire (10.11 I believe). If anyone knows of another newer driver that works, without a BSoD when enabling Crossfire, that would be great

 

[ActionableMango]

Crossfire and SLI have both been "a bag of hurt" for a long time. Theoretically it sounds good, but there are always problems with drivers and lack of game support. This has been true for years and years and years, so I expect no change. The only SLI solution I'm aware of that ever worked perfectly were the old 3DFX Voodoo cards.

I would say sell your two 5770s and get a 5870. One 5870 is about the same cost anyway, slightly better performance, no crossfire driver nonsense, full speed in OS X, less power, less heat, less cables, and you free up a couple of slots. Virtually any way you look at it, it's really the way to go.

 

[Borman]

I have a 2006 Mac Pro, not an option really, as its hit or miss. I am fine with dual 5770's, the only issue is the driver, but even that works fine with an older one so Im not worried about it.

 

[ActionableMango]

Right, sorry I forgot you have a Mac 1,1.

So is your MP able to have noticeable performance increase with 5770x2 Crossfire in Windows?

 

[Borman]

Yep, its quite nice. Obviously, its game to game, but being able to turn on AA/AF is great.