I’m looking for some eGPU buying advice for iMac 5K. Found some info on the US forum, but still unsure.
I play on a low-end 5K iMac (27", 2017) with its Radeon Pro 570. It runs ok at 50% render scale, if I keep the shadow quality setting low. But could be better.
I’m thinking about buying an eGPU to get better frame rates at higher settings (or higher render scale).
So now I’m wondering:
What eGPU enclosure should I buy?
What GPU should I put in it?
I don’t want to use a second monitor, so the eGPU would have to drive the built-in 5K display. I’m looking for a notable improvement, without compromising reliability. I have one Thunderbolt 3 port free.
I assume the safest bet is to pick from Apple’s supported GPUs list, right?
If you have a 5K iMac + eGPU setup, I’d like to hear about your experiences. Any issues? How big is the difference? Again, asking specifically for running the iMac’s built-in display with it.
You should only pick stuff labeled as supported as older stuff may not work. Apple like AMD GPUs right now so likely you would have to aim at RX 5700 XT or 5700. The eGPU box will be expensive as well.
As for performance improvements - WoW is often CPU bound and that iMac has an older Intel quad core, but that Radeon Pro 570 is weaker than RX 470/570 so it’s really really low for a 5K resolution - so an eGPU will help but at a premium. Radeon RX 5700 XT is ~273% relative performance on Techpowerup database.
(OP here, accidentally had an alt selected when posting…)
Thanks a lot for the advice, Bigkeg!
So I might try something like a Radeon RX 5700 XT and put it in a Razer Core X. That comes to about 850 €. Not cheap, but if it works it might be the best upgrade short of a new computer.
Would love to hear experiences how much that actually helps with the internal display. I understand you lose some performance there, compared to running a second monitor with the eGPU.
Some followup questions:
Does it matter what brand the card is (MSI, Asus, Gigabyte etc.) when using it with an eGPU enclosure on a Mac? And I see these “GAMING”, “MECH”, and “EVOKE” versions, too.
In the old days you had to hunt for a specific Mac version of a GPU - is that still the case with eGPUs, or should it be fine with any card that’s based on a supported GPU chip like RX 5700 XT?
Yeah sorry, this was totally a Mac-specific question. I would’ve asked on the US forums (they have a Mac-specific tech subforum), but seems like I can’t post there with my EU subscription. Let me know if we have a better forum to ask on the EU side.
340€ for Razer Core X + 515€ for the RX 5700 XT were just the first prices I found, haven’t looked around. So hence ~850€.
I know gaming on a Mac is, let’s say, very cost-inefficient, for various reasons. But WoW is pretty much the only game I play, and I have no desire to maintain a second computer (and dedicate desk space to it) just for WoW, or to deal with the hassle of using Bootcamp. So there we are.
That said, it’s still a lot of money, which is why I’d love to hear if others have had good or bad results with that setup.
The point i was trying to make is that even with the RX 5700 XT, you will have to make compromises at full 5K.
Also, don’t forget that performance in WoW is very dependant on the CPU.
Which CPU does your Mac have?
If that is also rather weak than you will get a “prettier” WoW with the new GPU, but not necessarily better FPS in raids or places with lots of players/npcs.
Another point is, increasing the viewing distance and environmental detail sliders will stress the CPU (settings above 7 are very demanding).
I understand. I’m not expecting perfection. Mostly looking to increase the render scale setting without sacrificing FPS too much. That should be entirely on the GPU, right?
It’s a good point about the CPU though. Mostly indoor content feels pretty playable (at 50% render scale, anyway). But I gotta check what FPS I actually get during a raid. And I guess I’ll have to tab out too (don’t tell them), to actually see what the CPU load is like. Probably 1 core at 100% and 3 idle…
Outdoors in newer zones is where it slows down most. Strangely, it doesn’t seem to be that affected by the distance sliders, so I have them at max. But I’ll test again. Are the distance sliders more GPU or CPU dependent? EDIT: Oops, you answered that already. Thanks!
It’s both. But more on the CPU.
Water on max is also very taxing.
Shadows too, but not as much as water or viewing distance/detail.
So an Intel I5-7500 with 2400Mhz RAM right?
The CPU is okish, but the RAM is pretty slow for todays standards.
Stable 60 FPS in bigger or progress raids will be off the table with that setup.
Should be more around 50 i would guess.
That is with all the usual raid addons ofc.
The real issue here is the bottleneck for the TB3 connection to the eGPU and then back again to the display. There is about a 20%-30% performance reduction using an eGPU and built in monitor.
So I went and bought the Razer Core X, and a put an RX 5700 XT (the “Gaming X” model from MSI) inside it. I got… mixed results.
Good news first:
When I connect it to an external 4K display, it works great. I get 60+ FPS with 100% render scale (which WoW settings actually called 5K, not 4K – go figure) and pretty good settings. Not everything was maxed, but I set it higher than I previously could.
Unfortunately, it barely works at all with the iMac’s internal display!
Forget the -20% or -30% performance penalty. It’s more like -80%. Far, far worse than the internal Radeon Pro 570. The same settings that give me ~55 FPS on the 570 got me 20-30 FPS on the RX 5700 XT. Even with everything at minimum, I couldn’t reach 50 FPS.
Worse, there’s a noticeable delay between me pressing movement keys and actually seeing the character move (or turn). This even extends to the 2D UI, with menu buttons highlighting way after the mouse moves over them. Completely unplayable.
Even with a TB3 bottleneck, it shouldn’t be that bad. I have the latest OS (10.15.5), which means I should have the latest AMD drivers, too.
So now I’m wondering what to do next.
I suppose there’s not much point trying different cards – the card itself clearly works fine, as does the eGPU enclosure.
There’s a chance it could be a faulty Thunderbolt cable, I guess. If that was the case though, I doubt I’d have seen such good results with the external display.
I could just return the whole thing , and settle for what I get with the internal 570. It’s not fantastic, but it’s completely playable.
Or perhaps I could consider moving to a system based on an external display, such as a Mac Mini. Would kinda make sense, since I already have the peripherals (external SSD, external HDD for backups, eGPU). I’d just need the Mini and a nice 4K display.
The large performance impact is bit odd, something TB3 itself should not do. You should ask about it on apple reddit/forums directly. It should be fixable unless Apple weird incompatibility.
Probably 1 core at 100% and 3 idle…
, and settle for what I get with the internal 570. It’s not fantastic, but it’s completely playable.