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Running dual 4870's in a 2009 Mac Pro

Interesting...

I just recently got a Mac Pro, this last Wednesday and this is something I have been looking into. I think I'm going to call Apple as well just to pick there brains and see what they say. Does anyone know if you are able to purchase the card outside of Apple's store?
 
Just Curious...

I've been doing some reading, and this may sound ridiculous, but if power wasn't an issue, would it be possible to install the ATi Radeon HD 4870 X2 card? While using OS X, you could just use the 4870, but when in Windows 7 or Vista could you then hook up Crossfire and be able to use the X2? Is this at all possible and if not I would just like to know why? Also, if this is not possible, would you need to have another 4870 with a miniDisplay Port or could you just get the HD 4870 that just has the Dual DVI, and be able to use the two in Windows using Crossfire? Thanks in advance
 
Ferrari904 said:
I've been doing some reading, and this may sound ridiculous, but if power wasn't an issue, would it be possible to install the ATi Radeon HD 4870 X2 card? While using OS X, you could just use the 4870, but when in Windows 7 or Vista could you then hook up Crossfire and be able to use the X2? Is this at all possible and if not I would just like to know why? Also, if this is not possible, would you need to have another 4870 with a miniDisplay Port or could you just get the HD 4870 that just has the Dual DVI, and be able to use the two in Windows using Crossfire? Thanks in advance
Click to expand...

In short, this is what the guys in this thread are attempting to do...
https://forums.macrumors.com/threads/661681/

Here we're talking about installing and running two Apple sanctioned ATI 4870's in one machine.
 
I have found the perfect solution to power an extra card.

http://www.fspgroupusa.com/FSPNEWS/BOOSTERX3.asp

It is 300w, and turns on from the power initial of a standard 4 pin molex connector (The one from cd drive where it gets installed).

It will be a neat setup rather. The only parts needed are:

2 x Apple ATI HD4870
1 x FSP BoosterX 3
1 x Crossfire interconnect cable

OS X will not work with crossfire but both cards should run stable. In windows crossfire should work.

My only problem is...where the hell can I source a FSP BoosterX 3 in Australia...no one sells them here :(
 
matthew.russo said:
I have found the perfect solution to power an extra card.

http://www.fspgroupusa.com/FSPNEWS/BOOSTERX3.asp

It is 300w, and turns on from the power initial of a standard 4 pin molex connector (The one from cd drive where it gets installed).

It will be a neat setup rather. The only parts needed are:

2 x Apple ATI HD4870
1 x FSP BoosterX 3
1 x Crossfire interconnect cable

OS X will not work with crossfire but both cards should run stable. In windows crossfire should work.

My only problem is...where the hell can I source a FSP BoosterX 3 in Australia...no one sells them here :(
Click to expand...

can you install that in a hdd bay if u want to keep a superdrive (and in the future a bluray drive)
 
KBS756 said:
can you install that in a hdd bay if u want to keep a superdrive (and in the future a bluray drive)
Click to expand...

Sadly no, it will take up your second bay. Also..the setup will occupy all of your PCI slots.

2 double wide cards + 1 for the psu


---PSU--- PCI-E x4
---VC2--- PCI-E x4
---VC2--- PCI-E x16
---VC1--- Space
---VC1--- PCI-E x16
 
Pili said:
I'm assuming it sits in the 2nd optical drive bay and you run some cable/connector down to the PCIe slot from the bay?
Click to expand...
Sorry should have said refer to the manual of the product. That is correct. A power cable runs to the pci-e slot cover...pretty neat installation.
 
Seems like a pretty solid solution. I wonder if the cable is small enough (or one can be diy'd) to fit on the pcie slot (3rd slot) the 2nd 4870 covers. That way you wouldn't have to give up that last top slot.
 
matthew.russo said:
Sorry should have said refer to the manual of the product. That is correct. A power cable runs to the pci-e slot cover...pretty neat installation.
Click to expand...

I really don't think that extra PSU will be necessary. Given that the MP power supply is designed to handle at least:
- 2x 2.93 CPU's
- 8x 4GB DIMMS
- 4x Hard drives
- 2x Optical drives
- 1x 4870 graphics cards
- 2x nvidia 120 graphics cards
- 1x RAID card

Unless your system has all of the above, I'd suggest you can sneak another 4870 onto the power grid without overloading the power supply! :p

You can power it in one of two ways without the extra power supply:
a) Use a pair of Y splitters so each card runs off one of the PCIe motherboard power headers...
CB-6M-68F.jpg


b) Use a SATA to Molex adapter as pictured then to PCIe from there.
SATA2MOLEX.jpg


c) To split the load use both (a) and (b)
 
matthew.russo said:
Sorry should have said refer to the manual of the product. That is correct. A power cable runs to the pci-e slot cover...pretty neat installation.
Click to expand...

There is already logistical issue with this product and mac pro - how do you mount something designed for open front 5 1/2 bay and relying for ventilation on front mounted curved fascia in a PC that has no open front 5 1/2 bay and no space for any fascia? How do you route additional power cable to the drive compartment all the way in front section?

VirtualRain said:
Given that the MP power supply is designed to handle at least:
- 2x 2.93 CPU's
- 8x 4GB DIMMS
- 4x Hard drives
- 2x Optical drives
- 1x 4870 graphics cards
- 2x nvidia 120 graphics cards
- 1x RAID card

Unless your system has all of the above, I'd suggest you can sneak another 4870 onto the power grid without overloading the power supply! :p
Click to expand...

All PSUs these days are split into sections, logic board is powered from one 12V rail, drives from the other, etc etc. For all we know the optical drive rail could be separated and designed to provide 60W/5A or worse yet, shared with remaining 4 SATA bays.
That said, I recon all you guys need is find fused molex to molex adaptor, like the ones used for surge protection and then molex to PCIe Y splitter. Power one connector for each card from motherboard and one from Y splitter. If both cards draw too much, worse case scenario - you'll blow a fuse.
 
Here's some more concrete data to work from...

TDP_manu_data.jpg


A 4870 requires 160W.

A GT120 (9500GT) uses 50W

As I mentioned above, unless your systems is configured to the max, you can be fairly certain there is headroom for an extra 100W from the PSU.

Now, each x16 PCIe slot can deliver 75W and each PCIe 6-pin PEG connector can deliver 75W. You can see that the 4870 barely requires 2 PEG connectors. It could almost get by with one.

So the two x16 slots can deliver 150W and the two PEG 6-pin connectors can deliver 150W so you are able to deliver 300W across those two slots and two connectors. Thus by wiring dual 4870's off the motherboard headers, you are only exceeding specs by about 7%... each PEG header and each x16 slot is only exceeding spec by a couple of percent.
 
v0n said:
There is already logistical issue with this product and mac pro - how do you mount something designed for open front 5 1/2 bay and relying for ventilation on front mounted curved fascia in a PC that has no open front 5 1/2 bay and no space for any fascia? How do you route additional power cable to the drive compartment all the way in front section?
Click to expand...

Looking at larger pictures of the FSP BoosterX 3, it would appear you can remove the black plastic fascia so it will fit in the 2nd drive bay. All the cables connect at the rear, it should be pretty simple to route the wiring.
 
Here's the manufacturer's power consumptions...

http://www.pcgameshardware.com/screenshots/original/2008/09/TDP_manu_data.jpg

4870 is 160W according to this.

As I said, the specs on a PCIe x16 slot is to be able to deliver 75w. Each 6-pin connector can also deliver 75W. Thus two x16 slots and two PCIe 6-pin connectors can deliver a total of 300W.

Two 4870's utilizing the existing power facilities in the case shouldn't cause any issues... especially since the machine was designed to run up to 4 lesser graphics cards at 50W each (200W total) through the PCIe x16 slots alone.
 
-SD- said:
Looking at larger pictures of the FSP BoosterX 3, it would appear you can remove the black plastic fascia so it will fit in the 2nd drive bay. All the cables connect at the rear, it should be pretty simple to route the wiring.
Click to expand...

I actually have one of these on my desk... It's 8" deep with the face plate which as you say can be easily removed. That would then make it 6.5" deep. You need an additional 2" or so clearance at the back for the power cable. Of course, removing the front would also remove the airflow through this thing, but honestly, I doubt that would affect it much... the power draw of a couple of 4870's is not going to put much tax on this thing.

How much space is available in the lower optical bay?

Having said all that, I'm fairly certain based on my calculations and past experience that you could power two cards from the existing PSU using techniques previous discussed.
 
VirtualRain said:
Here's the manufacturer's power consumptions...

http://www.pcgameshardware.com/screenshots/original/2008/09/TDP_manu_data.jpg

4870 is 160W according to this.

As I said, the specs on a PCIe x16 slot is to be able to deliver 75w. Each 6-pin connector can also deliver 75W. Thus two x16 slots and two PCIe 6-pin connectors can deliver a total of 300W.
Click to expand...

I don't think 160W is right - my 08 octo draws 206W with CPUs maxed out and ATI 2600 at idle and peaks 417W with CPUs maxed out and 4870 running crysis demo. So that's more than 210W already, before adjusting for overclocking. However, my 4870 is RV770XT rather than standard RV770 as used by Apple, so error might be there.
In any case - if we are speculating just 320W, out of which 150W is to be provided from PCIe x16 slots and further 150W provided from two connectors on the motherboard, then additional power supply becomes non issue - it would be just 20W short, that's less than regular drive, it can indeed be provided without any problems from a Y splitter.
 
Original poster:

These cables will not work. The Mac Pro uses a different 6-pin molex connector than what you had in your SLI PC. The Mac's connectors are smaller. It may look similar in the picture, but the SLI splitter cable you referenced will not fit the Mac Pro's motherboard connectors.

VirtualRain said:
On my old SLI PC gaming rig, I used a pair of PCIe 6-pin "Y" cables to serve two cards (both with dual power connectors) from one pair of PSU PCIe power cables.

Here's the product I used:
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=186&products_id=2664

I'm guessing, you could easily use this to add a second PCIe powered 4870.
Click to expand...
 
thagomizer said:
Original poster:

These cables will not work. The Mac Pro uses a different 6-pin molex connector than what you had in your SLI PC. The Mac's connectors are smaller. It may look similar in the picture, but the SLI splitter cable you referenced will not fit the Mac Pro's motherboard connectors.
Click to expand...

Just connect the Y cable to the end of the Apple supplied cables... the end that connects to the video card will be the same as any other.
 
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=115

here are some good pics on the unit.

I would reccomend running the card seperately not to stress the main PSU. Yes it's 980w, but under full CPU load, running large amounts of ram and hard disk, you would start to lose efficiency trying to run that card and a risk of breaking either the logic board os the psu itself. The only reason I am running with this psu is to safegaurd the rest of the mac pro itself. It is only designed to do so much. It should fit without the plastic face on it.
 
Would some kind soul please explain to me why Apple hates video cards and refuses to offer more than one or two for their computers, out of the dozens that ATI and Nvidia offer for sale. Thanks.
 
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