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Modern GPUs don't work in 2005 PowerMac?

rabidz7

Junior Member
Oct 21, 2014
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0
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I am currently using a stock 6600 GT and flashed 7800 GTX512 that will be connected to a 30" 2560x1600 Apple Cinema Display. The PowerMac has dual 970MPs at 2.5GHz (two 970MPs are about as fast as a single AMD FX-8300), will possibly have 20GB of DDR2 (currently have 16GB, but am going to order some more RAM today and see if it works), has two HDDs, a 500GB and a 2TB, and 32 total PCIe 1.0 lanes. The junk GPUs are holding the entire system back, but there is no way to upgrade them. When a GPU that is not flashed to a firmware compatible with the PowerMac is installed, the screen just stays black and the card doesn't initialize, even with OSes like Debian, which have drivers for modern cards.

Questions:
1.Why do cards to have modded firmwares in order to function?
2. Is 750 Ti is the fastest nVidia card that has one or no 6-pin PCIe power connector?
3. How hard would it be for someone who has no experience in any sort of programming other than markup to create a proper ROM for a card such as a GTX 750 Ti or R9 270?
4. How much would a programmer charge to create a ROM (I'm not looking to hire here; I'm just looking to find how much it would cost)?
3.
....A. If a 750 Ti had a firmware written, would it work in OS X 10.5.8, or would it only be usable in Debian due to lack of drivers?
....B. If a 750 Ti would not work, what is the fastest card that can be used in OS X 10.5.8?
 

Sheep221

Golden Member
Oct 28, 2012
1,843
26
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It is because Power computers had Motorola and IBM proprietary CPUs, it's not regular x86 CPU like FX or i7
 

rabidz7

Junior Member
Oct 21, 2014
10
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It is because Power computers had Motorola and IBM proprietary CPUs, it's not regular x86 CPU like FX or i7
I know that they are PowerPCs. PowerPCs are not proprietary at all; they just have never been as popular as x86 chips. But why does the fact that a CPU is a PowerPC cause GPU compatibility issues?
 

Ferzerp

Diamond Member
Oct 12, 1999
6,427
105
106
Because they use Open Firmware (which the cards don't support) and not BIOS or EFI.
 

rabidz7

Junior Member
Oct 21, 2014
10
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Because they use Open Firmware (which the cards don't support) and not BIOS or EFI.
Is there any way other than flashing to make a card work? I want to have a 750 Ti in my PowerMac without having to spend thousands to get a firmware written.
 

Mondozei

Golden Member
Jul 7, 2013
1,043
40
86
It's more than past time for you to upgrade. There literally isn't anywhere to run anymore, as per your thread.
 

Denithor

Diamond Member
Apr 11, 2004
6,300
23
81
Is there a particular reason you want to keep an ancient (2005) machine running today? Why try to upgrade just GPU when you could get much, much better performance with a whole system upgrade?
 
Feb 25, 2011
16,565
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Either that or go hang out at LEM and see what they tell you.

(two 970MPs are about as fast as a single AMD FX-8300)
This is complete bunk. Who told you that? Even a low end Celeron blows the 970MP out of the water.

Nothing "official" was ever released due to NDA, but the Developer Transition Kits that Apple shipped when they announced the Intel transition were, depending on the benchmark, competitive or even superior to the contemporary PowerPC Macs.
 
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Cerb

Elite Member
Aug 26, 2000
17,484
33
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Is there any way other than flashing to make a card work? I want to have a 750 Ti in my PowerMac without having to spend thousands to get a firmware written.
You can't. Buy an old card that was specified to run in said PowerMac, or get a new computer. PowerPC may not be proprietary, but the Mac firmwares were, and a EUFI/BIOS video card is unlikely to work.

In the best case, you might have a computer as fast as a bug-fixed 2-2.5GHz Phenom (I) (and that's assuming you do some number crunching work with it!), so it's way past time...
 

Cerb

Elite Member
Aug 26, 2000
17,484
33
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I am currently using a stock 6600 GT and flashed 7800 GTX512 that will be connected to a 30" 2560x1600 Apple Cinema Display. The PowerMac has dual 970MPs at 2.5GHz (two 970MPs are about as fast as a single AMD FX-8300)
No. The 970s were in the ballpark of a P4, clock per clock, with Altivec both holding them back and giving them a boost in work they were often used for. Late-model K8 CPUs were much faster, outside of vector math, and the Core Solo/Duo, then Core 2, simply demolished them. An FX-8300 may not be great by today's standards, but I'd bet it even leaves the 970MPs in the dust with no more than SSE2 getting used.

Apple wasn't a big enough market for IBM to care, and so history happened.

will possibly have 20GB of DDR2 (currently have 16GB, but am going to order some more RAM today and see if it works)
A new Intel or AMD system can easily handle 32GB, and LGA2011 type sockets can do 64GB.

The junk GPUs are holding the entire system back, but there is no way to upgrade them.
The system is old, and was slower than a 1-2-year old x86 workstation, or brand new midrange gaming rig, when new in 2005, save for OS X software support. Like Netburst, the 970s were supposed to scale in clock speed much faster than they did, and use less power at those higher clocks than they did (why AMD repeated this a decade later, we may never know).

1.Why do cards to have modded firmwares in order to function?
The GPU has to be configured so the OS can see it and use it, and so that you can get pre-boot video.
3. How hard would it be for someone who has no experience in any sort of programming other than markup to create a proper ROM for a card such as a GTX 750 Ti or R9 270?
Impossible. Even for people with extensive programming experience, that may be an impossible feat, due to differing expertise, and/or lack of sufficient documentation.
4. How much would a programmer charge to create a ROM (I'm not looking to hire here; I'm just looking to find how much it would cost)?
If they already were familiar with the GPUs enough to be able to make such a thing, I'm guessing well into the 5 figure range, if they don't have a, "real job." If they have said, job, and do work on the side, 6 figures.
3.B. If a 750 Ti would not work, what is the fastest card that can be used in OS X 10.5.8?
A used Quadro that has official support, likely found on eBay.
 

rabidz7

Junior Member
Oct 21, 2014
10
0
0
Is there a particular reason you want to keep an ancient (2005) machine running today? Why try to upgrade just GPU when you could get much, much better performance with a whole system upgrade?
I want a PowerPC-based system. I don't like x86. If you can find a system based on (a) Power8(s) for under $3000, I'd seriously consider it, but that isn't possible.
 

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