I’d be in trouble, since between ZFS and my various VMs, my system idles at ~170 GB RAM used. With only 32 I’d have to shut basically everything down.
My previous system had 64 GB, and while it wasn’t great, I got by. Then one of the motherboard slots died and dropped me to 48 GB, which seriously hurt. That’s when I decided to rebuild and went to 256.
Real question. Doesn’t the computer actually slow down when you have that much memory? Doesn’t the CPU need to seek into a bigger vast vs a smaller memory set?
No that’s not how it works. Handling a larger address space (e.g., 32-bit vs 64-bit) maybe could affect speed between same sized modules on a very old CPU but I’m not sure that’s even the case by any noticeable margin.
The RA in RAM stands for random access; there is no seeking necessary.
Technically at a very low level size probably affects speed, but not to any degree you’d notice. RAM speed is actually positively correlated with size, but that’s more because newer memory modules are both generally both bigger and faster.
The RA in RAM stands for random access; there is no seeking necessary.
Well there is, CPUs need to map virtual addresses to physical ones. And the more RAM you have the more management of that memory you need to do (e.g. modern Intel and AMD CPUs have 5 levels of indirection between a virtual and physical address)
But it also caches those address mappings, as long as your TLB is happy, you’re happy. An alternative is to use larger page sizes (A page being the smallest amount of RAM you can address), the larger the page the less you need recurse into the page tables to actually find said page, but you also can end up wasting RAM if you’re not careful.
I’d be in trouble, since between ZFS and my various VMs, my system idles at ~170 GB RAM used. With only 32 I’d have to shut basically everything down.
My previous system had 64 GB, and while it wasn’t great, I got by. Then one of the motherboard slots died and dropped me to 48 GB, which seriously hurt. That’s when I decided to rebuild and went to 256.
Oh yay, lemmy is finally popular enough to have a nobody asked e-peen guy!
NERD!
seriously, nice rig phat stats
Real question. Doesn’t the computer actually slow down when you have that much memory? Doesn’t the CPU need to seek into a bigger vast vs a smaller memory set?
Or is this an old school way of thinking?
No that’s not how it works. Handling a larger address space (e.g., 32-bit vs 64-bit) maybe could affect speed between same sized modules on a very old CPU but I’m not sure that’s even the case by any noticeable margin.
The RA in RAM stands for random access; there is no seeking necessary.
Technically at a very low level size probably affects speed, but not to any degree you’d notice. RAM speed is actually positively correlated with size, but that’s more because newer memory modules are both generally both bigger and faster.
Well there is, CPUs need to map virtual addresses to physical ones. And the more RAM you have the more management of that memory you need to do (e.g. modern Intel and AMD CPUs have 5 levels of indirection between a virtual and physical address)
But it also caches those address mappings, as long as your TLB is happy, you’re happy. An alternative is to use larger page sizes (A page being the smallest amount of RAM you can address), the larger the page the less you need recurse into the page tables to actually find said page, but you also can end up wasting RAM if you’re not careful.
You clearly know more than me, but wouldn’t everything from 4GB to 1TB have the same number of walks? And one more walk gets you up to 256TB?