Turn NUMA On or Off - Quick Trick

[TangoWhiskey9]

As one of many people with multiple 2p Xeon (and one 4p AMD) servers running both Linux and Windows I have a BIOS question that I'm hoping someone here can answer.

Does anyone have a quick like 4 point guide to NUMA that I can remember? Seems like I'm always using the Google to look up my processor combo plus OS to figure out if I'd need to set a new server up as on or off. Was hoping someone had a good trick to remember.

 

[mrkrad]

What o/s?

esxi (any other hypervisor) - numa on

old *nix SUMA - basically you are turning your 2P into old core2 design with a single front side bus.

I prefer to stick with 1p per bus - then there is no numa to worry about. two sockets and one bus is contention!

 

[dba]

I'm focused on databases, but I have done a bit of NUMA homework. The short answer for modern CPUs (AMD 6xxx or later and Intel 5600 or later, which have relatively small NUMA penalties) seems to be that it probably doesn't matter in most cases but that certain applications may benefit and others might be harmed by turning NUMA on/off.

As one of many people with multiple 2p Xeon (and one 4p AMD) servers running both Linux and Windows I have a BIOS question that I'm hoping someone here can answer.

Does anyone have a quick like 4 point guide to NUMA that I can remember? Seems like I'm always using the Google to look up my processor combo plus OS to figure out if I'd need to set a new server up as on or off. Was hoping someone had a good trick to remember.

 

[MiniKnight]

Interesting. So there is no real rule

 

[mrkrad]

SQL OS is numa aware. You can pin ram/storage/networking all together so if you have 16 sockets, its no sweat. With SQL 2012 and windows 2012 they communicate well but it's not perfect.

if a request comes through on IP 2.2.2.2 on socket 1 bus 1 - try to work it out without having to go ask socket 2 to do the work and send the results back to socket 1 bus 1 network card 2.2.2.2.

If you can afford it, it is far easier to just rock 1 socket per server westmere/nehalem. All that overhead goes away since the machine is now SUMA.

The biggest problem has been intel stuffing 2 sockets of cpu to 1 bus.

AMD will do 1 bus per socket.

DL360P gen8 is 2 sockets, 1 bus!

DL380P Gen8 is 2 sockets, 2 bus!