Re:IBM mainframe beats other platforms for cost and performance
by lucb1e on Saturday September 11, 2021 @03:48PM
(#28495242)
> Roughly 2GB of memory per server [...] so your VMs are going to be memory starved pretty much 24/7.
Most applications don't need gigabytes of memory though? I don't know what one uses a mainframe for but web servers, file shares, remote login software, proxies, traffic scrubbers... lots of common applications use up to a few dozen megabytes of RAM; throughput is much more important there and memory to operate on is just for some state and buffers. Even a database with millions of rows and a dozen indexed columns, the index of that (I just checked a database of my own) is in the hundreds of megabytes, far from even one gigabyte.
It seems a bit odd to assume each server always needs multiple gigabytes of RAM.
Most applications don't need gigabytes of memory though? I don't know what one uses a mainframe for but web servers, file shares, remote login software, proxies, traffic scrubbers... lots of common applications use up to a few dozen megabytes of RAM; throughput is much more important there and memory to operate on is just for some state and buffers. Even a database with millions of rows and a dozen indexed columns, the index of that (I just checked a database of my own) is in the hundreds of megabytes, far from even one gigabyte.
It seems a bit odd to assume each server always needs multiple gigabytes of RAM.