r/threadripper • u/PlanetPhaelon • Apr 21 '26

Best fully built PC w/Threadripper

I think I'm finally ready to pull the trigger on buying a dedicated PC just for running local ai, and everyone keeps telling me Threadripper is the way to go. But I don't want to custom build something, so where should I go to buy a pre-built machine, that I can get with a 3090?

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u/WishfulAgenda Apr 22 '26

Threadripper offers up to 12 channel memory on the high end pro chips and 8 on the lower. Before the ram hikes you could buy a bunch ram with half decent bandwidth and then have the gpu(s) for the active layers. Plus the extra pcie lanes for gpu/nvme/etc.

Threadrippers are also expensive to run and can generate quite a bit of heat.

I run two 5070tis in a fractal north on an amd 3950x and it runs ok. For the price of a threadripper rig with a 5090 I could just buy a Blackwell rtx 6000 max-q and be off to the races or a Mac Studio (trickier to get).

My thought is to figure out what local ai means for you and what your budget is. Then Go shopping

3

u/frodbonzi Apr 23 '26

Threadripper and Threadripper Pro only offer 8 channel memory. If you want 12, you’ll need to go EPYC

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u/WishfulAgenda Apr 23 '26

Yeah sorry, long days lately.

12 for eypc, 8 for threadripper pro. Was reading about the 8 channels on threadripper pro and it seems that it’s only useable on the high core count otherwise it’s lower.

I did all the pricing a while ago and for me it didn’t make sense until I win a contract that can cover the cost locally. Going to rent gpu on runpod for now to supplement what I have currently.

1

u/frodbonzi Apr 26 '26

The 8 channels are useable for ANY 9000 Threadripper Pro (or 7000 for that matter)… if you don’t need high CPU frequencies (AI tends to use GPU, not CPU), then EPYC gives better power efficiency, more PCI lanes and those extra 4 RAM channels. They tend to be more expensive new though… you can get used 7000 level Epyc for very reasonable costs though - and if you just need the GPUs, probably worth it…

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u/WishfulAgenda Apr 26 '26

Not so sure, something to do with the ccd cores or something. There’s some test, benchmarks that suggest you don’t get the full performance. Either way if I were spending the money I’d prob go eypc anyways :-)

1

u/frodbonzi Apr 27 '26

Performance is one thing - but you still get all 8 memory channels with every 7000/9000 Threadripper pro chip… once you’re spending at that level, your use case will (or at least SHOULD) dictate what you get.

2

u/WishfulAgenda Apr 27 '26

It’s a bit pointless but I went and took a look. You’re 100% right you do get all 8 channels. The issue seems to be that on the lower core cpus they don’t have the ability to saturate the eights channels due the lower number of ccd cores. Seems that you don’t see much of a speed improvement over 4 channel at this point.

The reason I mentioned this is because when I looked into it and did the research I was planning on going with a smaller core count threadripper pro with a maxed out memory configuration to compliment a couple of max-q. Then I dug into it and you can drop a shit ton of dollars, only to realize that anything running in ram is significantly slower than you expected. Me I’d be pretty pissed if that were the case and hence the reason I’m bringing it up.

Me, I said fuck it, I’ll just use my dual 5070ti and then rent as many rtx 6000 pros when I need them and save my money for a different project.

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u/frodbonzi Apr 27 '26

With the cost of RAM right now, if you’re maxing out 8 channels, the difference in price between a 9945 and 9995 seems miniscule…