Re: [Qemu-devel] ridiculously slow VM memory performance on Ryzen CPU

On 2018年04月25日 21:18, Daniel P. Berrangé wrote: > On Wed, Apr 25, 2018 at 05:48:42PM +0800, Qu Wenruo wrote: >> Hi, >> >> When testing IO heavy work on my VM backed by Ryzen 1700 CPU, I turned >> to brd modules, but surprisingly, the speed is even slower than some HDD: >> >> --- >> $ sudo modprob

Re: [Qemu-devel] ridiculously slow VM memory performance on Ryzen CPU

On Wed, Apr 25, 2018 at 05:48:42PM +0800, Qu Wenruo wrote: > Hi, > > When testing IO heavy work on my VM backed by Ryzen 1700 CPU, I turned > to brd modules, but surprisingly, the speed is even slower than some HDD: > > --- > $ sudo modprobe brd rd_nr=1 rd_size=1048576 > $ dd if=/dev/zero of=/dev

[Qemu-devel] ridiculously slow VM memory performance on Ryzen CPU

Hi, When testing IO heavy work on my VM backed by Ryzen 1700 CPU, I turned to brd modules, but surprisingly, the speed is even slower than some HDD: --- $ sudo modprobe brd rd_nr=1 rd_size=1048576 $ dd if=/dev/zero of=/dev/ram0 bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 byte