Why no 2X ATI Radeon HD 5870 on BTO page?

[sparkie7]

Theres 2X 5770 but not for the 5870 -- is it b/c of the power draw requirements?

[peskaa]

Yes, and not enough feeds off the logic board to provide the power.

[sparkie7]

ok thanks. there's no 1x of each, so assuming there's not even enough power to run one of each. bummer..

what's better 2x 5770's or 1x 5870 -- to drive 3x 30 ACD's

I assume its the 2x 5770's?

[DigitalVT]

ok thanks. there's no 1x of each, so assuming there's not even enough power to run one of each. bummer..

what's better 2x 5770's or 1x 5870 -- to drive 3x 30 ACD's

I assume its the 2x 5770's?

Well I ordered mine with one 5770 with the idea of adding a 5870 later when they become available, surely there will be enough power for this!!!

[peskaa]

There are two feeds off the board in total. The 5770 uses one, so you can have two cards. The 5870 uses two, so you can only have that single card installed.

The way round it, of course, is to install a 5870 and then have a GT120 (or several) for extra screens, as they don't need power feeds and OS X copes fine with a mix and match of GPU vendors.

For running three 30"ers, yes, the pair of 5770s. You can't Crossfire the boards, but you'll get better performance on a whole.

[DigitalVT]

There are two feeds off the board in total. The 5770 uses one, so you can have two cards. The 5870 uses two, so you can only have that single card installed.

I was thinking of getting maybe a third power feed off of the unused (2nd) CD/DVD tray??

[Cindori]

I was thinking of getting maybe a third power feed off of the unused (2nd) CD/DVD tray??

i thinks thats sata power, dunno if there are adapters

[nanofrog]

The best way to safely run a second 5870 (or 5770 + 5870, or even 2x 5770's + 1x 5780), is to run a separate power supply.

The easiest way to do this, is by using a graphics card PSU that's meant to fit in a 5.25" bay (here (http://www.newegg.com/Product/Product.aspx?Item=N82E16817101044&cm_re=power_supply-_-17-101-044-_-Product)). Cheap too. If the second optical bay is used, then run it externally (not pretty, but better than a PC PSU due to the mess of unused wiring, and no need to jump the green and black wires to make it work).

As per the idea of pulling the power from the backplane connector located at the empty optical drive (power + data), I wouldn't recommend it. It's not likely to be able to provide sufficient current, and could actually damage the system.

Nor would trying PSIG Y splitters (again, too much current on the rail, and in this instance, melt the solder for the traces on the backplane board = short circuit, resulting in a new backplane board needed; board that has the PCIe slots on it).

[Concorde Rules]

The best way to safely run a second 5870 (or 5770 + 5870, or even 2x 5770's + 1x 5780), is to run a separate power supply.

The easiest way to do this, is by using a graphics card PSU that's meant to fit in a 5.25" bay (here (http://www.newegg.com/Product/Product.aspx?Item=N82E16817101044&cm_re=power_supply-_-17-101-044-_-Product)). Cheap too. If the second optical bay is used, then run it externally (not pretty, but better than a PC PSU due to the mess of unused wiring, and no need to jump the green and black wires to make it work).

As per the idea of pulling the power from the backplane connector located at the empty optical drive (power + data), I wouldn't recommend it. It's not likely to be able to provide sufficient current, and could actually damage the system.

Nor would trying PSIG Y splitters (again, too much current on the rail, and in this instance, melt the solder for the traces on the backplane board = short circuit, resulting in a new backplane board needed; board that has the PCIe slots on it).

Seems like a waste of time, money and energy when the Mac Pro has a 1200W PSU available.

I'm sure you could make or find some adapters that can draw the power off the SATA connectors... :p

Edit: Assuming the SATA connectors have a decent enough power rating.

If your really brave then opening up the PSU to take another feed off there would be a way forward :p Although warranty issues!

[peskaa]

If your really brave then opening up the PSU to take another feed off there would be a way forward :p Although warranty issues!

And the cabling for such would be a nightmare. Finding space for optical drive into PCIe bay leads is hard enough...

[Cindori]

And the cabling for such would be a nightmare. Finding space for optical drive into PCIe bay leads is hard enough...

there is hole in the optical area bottom that comes out at 1st harddrive

[barefeats]

The best way to safely run a second 5870 (or 5770 + 5870, or even 2x 5770's + 1x 5780), is to run a separate power supply.

The easiest way to do this, is by using a graphics card PSU that's meant to fit in a 5.25" bay (here (http://www.newegg.com/Product/Product.aspx?Item=N82E16817101044&cm_re=power_supply-_-17-101-044-_-Product)). Cheap too.

Brilliant. In the past, I used an external modified ATX 500W power supply to drive dual GPUs that required two power feeds each. It was not a pretty sight with the side cover off and power cables running from the ATX to the PCIe bay.

The Optical Bay PSU is a more elegant solution if you want to run dual 5780s. If you are running Windows via Boot Camp, you should be able to jumper them with a CrossFire connector (assuming that connector isn't covered up).

[Transporteur]

there is hole in the optical area bottom that comes out at 1st harddrive

That way you'd block the first hard drive and you wouldn't be able to slide in the optical bay any more.

There is however allocated space around the upper left corner of the logic board. The optical bay SATA cables also run through there and there is more space for additional cabling.
All it takes is to disassemble the front PCIe fan and the supply cable cover behind the optical bay.

There is, however, no way to force two 6 pin connectors through there. Taking of the connectors should work though.

[Cindori]

That way you'd block the first hard drive and you wouldn't be able to slide in the optical bay any more.

There is however allocated space around the upper left corner of the logic board. The optical bay SATA cables also run through there and there is more space for additional cabling.
All it takes is to disassemble the front PCIe fan and the supply cable cover behind the optical bay.

There is, however, no way to force two 6 pin connectors through there. Taking of the connectors should work though.

wtf u talking bout? :)

<log in to see this pic>
http://att.macrumors.com/attachment.php?attachmentid=165461&d=1238716130

[Transporteur]

wtf u talking bout? :)



:p
Unfortunately I can't see anything on that pic. I just made a quick one.

http://a.imageshack.us/img844/1886/dsc09696.jpg

As you can see the '09 and thus the '10 models don't have any holes in the bottom plate. You can however access the ODD bay through the space on the left.
All you have to do is remove the power supply cable cover and the front PCIe fan.

[Cindori]

hm. well it seems that the hole is still there but there is a cover on the back, hiding it. then we are speaking of the same hole. good pic.

at least on the 06 you could fit a cable there. but yeah it's tight, took me about 10min to force a molex through.

[Spanky Deluxe]

You can buy six pin pcie power cable y-solitudes to power two 5870s. Of course, you'd be running more power through the tracers on the board than they were specified for. I remember people having some stability problems powering a second card from the optical bay but I ran two 4870s in this manner in my Mac Pro for about seven months without issue before upgrading.

[nanofrog]

Seems like a waste of time, money and energy when the Mac Pro has a 1200W PSU available.
It's to do with how the +12V rails are used.

There's no actual statement of the PSU size in the specification page (http://support.apple.com/kb/SP589), just voltage and current consumption (which are peak values BTW). But even if it actually is a 1200W unit, that's likely a peak rating, not a continuous one. So take that number and divide by SQRT 2 (1200W/1.414) = 850W. If it's the same as previous models (980W), then the continuous power rating would = 980W/1.414 = 700W.

I'm sure you could make or find some adapters that can draw the power off the SATA connectors... :p
Yes, there are adapters out there (indirectly, so multiples would be required; and possibly modified for gender).

Edit: Assuming the SATA connectors have a decent enough power rating.
They don't. Worst case, it's meant to handle ~40W (peak power draw of a mechanical drive during spin up).

If your really brave then opening up the PSU to take another feed off there would be a way forward :p Although warranty issues!
You'd need to know what rail goes where, what the current load is on each, and what they're rated for in order to determine you can draw sufficient power. You can't just tie them together either, as the voltage regs usually are not using matched components (transistors for example) = uneven power draw that will burn one, then the other out.

You can buy six pin pcie power cable y-solitudes to power two 5870s. Of course, you'd be running more power through the tracers on the board than they were specified for. I remember people having some stability problems powering a second card from the optical bay but I ran two 4870s in this manner in my Mac Pro for about seven months without issue before upgrading.
I recall one person for sure that tried this, and burnt out their board. :eek: The solder on the traces melted, causing a short that in turn, burnt it out. :(

Not good IMO.

[Justinf79]

The way round it, of course, is to install a 5870 and then have a GT120 (or several) for extra screens, as they don't need power feeds and OS X copes fine with a mix and match of GPU vendors.

So can OS X use both the GT120 and 5870 together in OpenCL stuff?

Also, how will Win7 handle this setup? I ask because I have a GT120 atm, and thinking about getting the 5870 when it's available.

[cured.not.dried]

So can OS X use both the GT120 and 5870 together in OpenCL stuff?

Also, how will Win7 handle this setup? I ask because I have a GT120 atm, and thinking about getting the 5870 when it's available.

gt120 doesn't do openCL

and windoze hates cards from different vendors being present, although you should just be able to disable the gt 120 in the devices control panel.

[cured.not.dried]

The easiest way to do this, is by using a graphics card PSU that's meant to fit in a 5.25" bay (here (http://www.newegg.com/Product/Product.aspx?Item=N82E16817101044&cm_re=power_supply-_-17-101-044-_-Product)). Cheap too. If the second optical bay is used, then run it externally (not pretty, but better than a PC PSU due to the mess of unused wiring, and no need to jump the green and black wires to make it work).


how would one power that 5.25" bay PSU without leaving the case open? i'm really interested in this, but i don't wanna have my case open cause kitty loves to rub up on my computer when i don't pay attention to her...

[Justinf79]

gt120 doesn't do openCL

and windoze hates cards from different vendors being present, although you should just be able to disable the gt 120 in the devices control panel.

Actually the GT120 is supported.
OpenCL
requires one of the following graphics cards or graphics processors:

NVIDIA GeForce 320M, GeForce GT 330M, GeForce 9400M, GeForce 9600M GT, GeForce 8600M GT, GeForce GT 120, GeForce GT 130, GeForce GTX 285, GeForce 8800 GT, GeForce 8800 GS, Quadro FX 4800, Quadro FX5600
ATI Radeon HD 4670, ATI Radeon HD 4850, Radeon HD 4870

http://www.apple.com/macosx/specs.html :)

[goMac]

gt120 doesn't do openCL

and windoze hates cards from different vendors being present, although you should just be able to disable the gt 120 in the devices control panel.

Uh, no, the GT 120 most certainly DOES do OpenCL. I've used OpenCL on my GT 120.

http://www.nvidia.com/object/io_1252000156987.html

[Vylen]

There's no 2x 5870 option because doing so would set your Mac Pro on fire...

On a related note, just how much heat do they generate? :p

[goMac]

and windoze hates cards from different vendors being present, although you should just be able to disable the gt 120 in the devices control panel.

Also, I should mention that VISTA hated cards from different vendors, that was fixed in Windows 7.

[Wild-Bill]

There's no 2x 5870 option because doing so would set your Mac Pro on fire...

On a related note, just how much heat do they generate? :p

I believe that two (2) 5870's generate exactly one HALF the heat of one nVidia Fermi card. :p

[skiffx]

Also, I should mention that VISTA hated cards from different vendors, that was fixed in Windows 7.

Thats good, I thought I would need to disable my gt120 under windows and run only the 5870...

[skiffx]

I believe that two (2) 5870's generate exactly one HALF the heat of one nVidia Fermi card. :p

lol :D

[deconstruct60]

B
The Optical Bay PSU is a more elegant solution if you want to run dual 5780s.

Not really. Note where venting the heated air from this additional power supply. It will be vented directly at the other power supply. ( There is a post above with a picture of the location. There is an air moving fan at the rear of the chamber which is meant to take very lightweight opticial drive waste heat and to more primarily send non high temperature air at power supply.

Any care to pony up a design of another computer where the power supplis vent serially into one another? Don't think you going to find one. ... hence not particularly elegant.

Chuckle folks looking for where to run the PCI-e power cord down to graphics card thermal zone. Note you also need to run AC out also. (again typically much more easily done by in generic PC case by running it out an unsued PCI-e slots bracket hole. (again running a AC power cord through mutliple heated air thermal zones. ... elegent ? )

It is a cute hack. Elegant not. Working in the short term isn't necessarily elegant.


That unit pointed to on newegg probably vents front to back. In the generic PC case design, there usually is nothing directly behind the CD drive slot and that unit will in most configs vent how air into the case's general internal air volume. Typically most PC cases (where folks are likely put plug in two higher range graphics cards) have a number of fans attached in verious locations around the case to current some kind of tornados to eventually blow the hot air out after it is spun around internal for a while.

You are going to pump more heat into the top thermal zone that it was designed for. Minimally even if that is a 85% effecient supply looking at top end of 68 W and if at half 35W .

The top thermal zone has to garbage collect what the bottom two to miss anyway. So there likely is some slack that it can take up. However, this device will likely also increase what is coming out of the mid case also.


You would be pumping more wattage into the midcase thermal zone that Apple probably designed for since they capped the amount of power distributed into that zone. (docs stats there is 300W for PCI-e slots). There is probably some buffer over that, but will be likely removing all the safety margins they may have built in.

The 5870 have a TDP around 188 and the 5770 around 108. Pairing up the two is 296W which is probably close to thermal dissipation target for that midcase zone. 376W is likely going to put the cooling behind the curve if actually start stressing the card.


Common sense folks. If you stick more that 900W of stuff inside the case you are exceeding the design. There is no way Apple designed the box to dissipate more heat that the wattage on the power supply.


Elegant would be something that perhaps pulled more air out an open PCI-e backet hole with funnel to a relative wide dimensional fan and up over the externally mounted power supply. That subsystem would at least attempt to remove some fraction of the additional power pumping into the case. The AC cord would not have to routed out of the box either. Coming in through the PCI-e bracket hole means going to be relative close to the card routing power too so aren't string wire over long distances internal to box disrupting air flow.

This? this is "oh look a square hole I can plug my square box into". There's no attention paid to overall system impact or synergy.

[nanofrog]

how would one power that 5.25" bay PSU without leaving the case open? i'm really interested in this, but i don't wanna have my case open cause kitty loves to rub up on my computer when i don't pay attention to her...
Out of a PCI bracket in an unused PCIe slot.

The other option is to leave the PSU unit external, and run the PSIG cables into the case (may require mods to the PSIG power cables or case, as I've not had access to the unit linked).

As per the thermal issues, there's merit there, but it's been used before by others (no complaints of overheating that I recall). You could also push the fan speeds up a bit if needed as well (still a compromise as it can add ambient noise to the work environment, and increased wear to the fans).

Neither is ideal (internal/external), but it's a solution that will do the job given the MP's internal design. Unfortunately, anything not offered by Apple tends to be this way.