[15:42] ahoi ubuntuland! === Maaz_ is now known as Maaz [15:47] hi inetpro [15:47] theblazehen: how are you doing? [15:47] Good and you inetpro ? [15:47] all good thanks [15:59] theblazehen: what can you tell me about running virtual machines with 32bit Ubuntu server on a 64bit KVM host environment? [15:59] good idea / bad idea, or does it even make a difference? [16:02] inetpro: Depends on workload inside the VM [16:03] I'm assuming you won't be needing more than 4 GiB RAM inside the guest? [16:04] 32 bit will use 32 instead of 64 bit pointers, so less overhead there, but misses out on cool x64 features [16:04] Check out that top bit of https://en.wikipedia.org/wiki/X32_ABI for a TL;DR [16:15] ubuntu doesn't use x32 though does it, just standard x86 (i386)? [16:19] note also that x32 (which sadly probably isn't what you will get) only limits to 4GiB per program, so you can still use more than 4GiB in total [16:19] if I just need a server with less than 2GB of RAM surely 32bit will be more effective on resources? [16:20] s/effective/efficient/ [16:23] sure, but if it's x86 it wastes half the registers and a bunch of other fancy cpu capabilities [16:23] x32 is meant to be the compromise between the two - but I'm unaware of any mainstream binary distro offering it as an option [16:24] hmm... and most developers now have 64bit, so I guess 64bit is probably safer to go as well? [16:28] I would not expect much difference in terms of stability at this point [16:28] either way [16:32] thanks for the inputs [16:32] "ubuntu doesn't use x32 though does it, just standard x86 (i386)?" MaNI Yeah, wasn't recommending it, it just had a great TL;DR of the (dis|)advantages of each [16:33] am not sure what exactly is in this ISO ubuntu-14.04.5-server-i386.iso [16:34] inetpro: That's normal 32 bit [16:34] I have a machine with that running, how do I check? [16:34] i386 = normal 32 bit indeed [16:34] `uname -p` [16:35] i686 [16:35] short version. x86 (i386/i486/i586/i686) can have smaller binaries and less memory but uses less of the CPU [16:35] x86_64 uses all of the new cpu features, but often makes programs use more memory [16:36] x32 is meant to be the best of both worlds but isn't really available for anyone who isn't a cutting edge power user to use [16:36] MaNI: yah, that last point is the big problem going forward [16:37] despite the above there are certain workloads where x86 can outperform x86_64, but for the most part x86_64 will perform better YMMV [16:37] 👍 Nice summary MaNI [16:39] x86 binaries also tend to suffer in that they are built for the 'lowest common denominator' of x86 cpus - and x86 cpus date very far back. So they often don't take full advantage of some of the new x86 cpu features even... While x86_64 does not have such a long history so x86_64 binaries make use of more modern features [16:40] but people who compile for themselves like myself can side step this (for example) - so it's hard to get proper comparisons even when you look at benchmarks etc. [16:41] afaik programs can do feature detection, and use faster instructions if they are available? [16:42] some can certainly [16:43] and especially things like video compression libraries generally do, much like facebook relationships "it's complicated" :( [17:00] haha [18:26] Ubuntu!