Threadripper - do i need mega ram?

[davision]

Thinking about getting a threadripper machine. Since it has so many cores -- and each core needs its own memory (right?) -- does that mean I need to get mega-ram? Like 64 Gig?

I'm worried about it being memory depleted and failing renders. I don't do super memory intensive scenes but most of my farm has 16gb with only 4 or 6 cores -- so 4/gb per core. Just wondering I need to have the same ratio for the 'Ripper.

[Richard7666]

I'm not sure what you mean by "each core needs it's own memory", but nah. I mean, most people aren't going to be filling all 8 DIMMS are they?
What you *Do* need to ensure is that your memory is installed in a quad-channel configuration. You can run it in other configurations, but you may as well not have bought TR in that case.

Also, I believe the connection between the two dies (TR is basically two Ryzen 1800s stuck together) runs at your memory speed, though am unsure how much effect this has in practice.
Probably best not to go buying DDR4 1600 or something though. The default is 2133 so get at least that, ideally faster.

[davision]

I'm not asking about memory configuration, or the amount of DIMMS -- I'm asking about total memory capacity and it's usage.

When rendering I thought I read that memory is divided among each core. If you have 16GB of RAM on a 4 core machine, then each core gets 4GB. If you have 32GB of RAM on an 8 core machine -- again each core ends up with 4 GB. Therefore, if I am running Threadripper (16 cores), I'd need 64GB to get the same memory allottment per core. I don't know if it's true - but I did read something to this effect.

[delineator]

I'm not asking about memory configuration, or the amount of DIMMS -- I'm asking about total memory capacity and it's usage..

I mean, thats the same thing, isn't it? Ram only comes in specific configurations and assuming your running quad channel (with TR you should be), then it really boils down to chip density because alot of decisions are made for you.

I think you MIGHT be referencing the uma vs numa stuff, but I'm honestly not sure. Have you read up on the NUMA stuff? Or by "When rendering I thought I read that memory is divided among each core" do you mean just in general, across any platform?

Either way, I wouldn't worry about it - get as much ram as you think you need, its all good.

[Neilg]

When rendering I thought I read that memory is divided among each core.

It's not. 16gb is 16gb no matter how many cores you have.
multiple separate processors can get complicated, but maybe only in server setups? I'm not sure, but I do know you have nothing to worry about.