Classic Mac Pro Fettlage

It's been a little over a month since I transplanted the GTX 1060 from my PC into my cMP, which I liked a great deal. I wasn't as happy with the replacement card I'd put into the PC (GTX 1650 Super) as it just annoyed me slightly sonically, and it didn't appear to be any improvement whatsoever over the GTX 1060. Now I never wanted the GTX 1650S, it was just what I was able to get my hands on. What I actually wanted was either 6GB GTX 1060 or preferably a GTX 1070. About a month later I finally managed to snag a GTX 1070 for sensible money that hadn't been a mining card. I dropped it into the cMP to test it.

It may be small but it's also quiet

As expected the Mac drivers aren't a patch on the PC ones so the 3GB GTX 1060 in the PC is outperforming the GTX 1070 in the Mac to the tune of 9fps in Haven (Ultra, 1920x1080, Normal tessalation. 85fps vs 94fps). However when the GTX 1060 was in the Mac it was nowhere near as quick. I can't remember what it got, but it was over 60fps to be fair to it, and that's all that really matters. I had to back off the Valley benchmark to get it over 60fps on that, whereas on the GTX 1070 I can go ultra and it's comfortably over 60fps.

As long as everything can run at a v-synced 60fps, it's all I really need. I'm not about to go out and blow hundreds on a G-Sync monitor so anything more is moot really. I just found it interesting that a GTX 1070 has to brute force it's way in a Mac and ends up being slightly slower than a GTX 1060 in a PC. That said, both of them comfortably manage over 60fps most of the time and that is all I require them to do.

Now for some observations about running a Nvidia card in a Mac: Don't update your OS until you know there's a matching update to the driver! This caught me out as when I rebooted it blank-screened as the drivers no longer worked. Thankfully the new web drivers had been released, but I needed to put the Radeon back in to install them after essentially breaking the Nvidia drivers with the OS update. Another interesting difference between the two Nvidia cards is that the GTX 1070 isn't causing power spikes like the GTX 1060 did that would cause the PSU to have a bit of a spasm. The Mac's PSU fan is now back in the control of the OS and it's now behaving nicely. I have to admit that was slightly odd and worrisome behaviour from the GTX 1060 and was another feature that made me choose to keep the GTX 1070 in the cMP.

The next update was out of necessity as I was running out of storage. Where I'd liked to have scored a bigger NVMe drive, I got what was available in a model I knew would work with low hours on it for sensible money. I've tried to snag a bigger one in the meantime but haven't been successful. So time to strap on 1TB of SSD, but again we come to the limitation of the SATA 2 bus. So rather than do that I've fitted a pair of 480GB SSDs in Raid 0. This is in an attempt to get something like the performance of a single SSD on a SATA 3 bus out of the pair of them over SATA 2. That's the idea anyhow. The results are below and are what was expected.

Where next? I/O is another area of the cMP that can be brought up to modern standards quite easily. The WiFi and Bluetooth is on a mini PCIe card lurking behind the CPU tray that can be swapped out by means of an adaptor and some cable extensions with one from a later iMac. This gives us wireless AC and Bluetooth 4.0, enabling Airdrop, hand off and Apple watch sign in. The other nice to have would be a Sonnet Allegro Pro USB 3.2 Type A PCIe card to replace the USB 3.0 one I currently have. It would allow charging on all the ports and the connection of some modern devices at 10Gbs. Both these upgrades are big money for something I simply don't need right now. Something for later maybe if the prices come down.

Once again I hope this mini blog shows what a magnificent machine the cMP was. How it, like the PowerMac's before it (of which I've had many), filled a niche that the home Mac enthusiast has been crying out for since Apple brought out the trashcan. It's such a versatile machine, which I know can be the antithesis of Apple at times, but it's something that since the Apple II has been part of their make up. Please bring it back. But without that T2 bollocks... That currently prevents me considering any modern Mac as a viable long-term platform. Having a chip that bricks the machine when the SSD drives dies out of warranty is just not friendly to the enthusiast user.

UPDATE: A couple of OS updates later and I got sick of having to pull the 1070 out and replace it with the Radeon. To be fair, I don't lean on the GPU particularly heavily in this machine so I've dropped that into the PC which I use purely for gaming, sold the 1060 and have replaced the 7950. It's not without it's modifications however!

The fan noise of the Radeon when under heavy load was LOUD, shockingly so. So I've removed the stock fan shroud, got a mini 4-pin PWM Y-cable from eBay, and added a pair of 120mm Noctua NF-P12 Redux PWM 1700RPM fans to it with cable ties. They are virtually inaudible at idle and barely at 60% where the temp stabilises with the highest load I can throw at it (Heaven benchmark). That'll do.

UPDATE 2: The fastest fully compatible card you can get that doesn't require any drivers or PSU mods is the Radeon RX 580. They were fitted as standard in Apple's eGPU enclosures and are therefore fully supported as long as they have a Mac EFI BIOS. That is awkward as you need a specific card with the right memory, then you need to unsolder the BIOS write a new one and solder it in. With the excessive prices of GPUs over the last few years post COVID, this has meant that getting a fully Mac compatible card has been very expensive. Well I've finally bit the bullet.

I've been lucky enough to snag one for sensible money and I had no problem spending a little extra for not having to go through the ball ache of actually doing the job myself.

It behaves well. I'm very happy with the temps and noise, so there's no need to fettle it. It's just in, it's fast and it works. If I can stretch out running this machine for as long as possible, then I'll be a very happy chappy. Easily the best Mac ever made.

[ Part 1 | Part 2 ]

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