Using qemu32 instead of default qemu64.

[ozgurerdogan]

While playing with cpu types for my kvm guests, I noted qemu32 run noticable fasted than default qemu64 one. What do you think? I am currently switching to qemu32 cpu types... Could there be faster cpu type than qemu32? My kvms are 32bit...

 

[RCK]

Interesting, what version of KVM / proxmox are you using ?
What kind of benchmark did you use ?

thx

 

[dietmar]

I noted qemu32 run noticable fasted than default qemu64 one. What do you think?

I thing that completely depends on the benchmark you use.

 

[ozgurerdogan]

I thing that completely depends on the benchmark you use.

What do you mean with "benchmark"? I have hp, ibm and also oem servers. qemu32 runs about %20 faster I guess.

 

[dietmar]

qemu32 runs about %20 faster I guess.

What do you mean by 'I guess'?

 

[ozgurerdogan]

What do you mean by 'I guess'?

I mean I see at least %20 better performance with qemu32 than qemu64. What is the difference between qemu64 & qemu32? is it like x86 and x64?

 

[dietmar]

I mean I see at least %20 better performance

Again, how do you measure that?

 

[RCK]

Yes, is it just a feeling or can you measure the startup time of one application ?, etc.

 

[ozgurerdogan]

Yes, is it just a feeling or can you measure the startup time of one application ?, etc.

As I said "I noted qemu32 run noticable faster" meaning, I feel it like so. I did not benchmark it if you mean so.

 

[dietmar]

64bit application use more memory (about 2 to 4 times). That can sometime slow down things. But usually 64bit is as fast as 32 bit.