Solved with MTRR was: ISSUE: very slow (factor 100) 4-way 16GByte server, with 2.4.2

Thanks everyone, especially David, for explaining the MTRR problem to me in detail. I could get the machine to work nicely by mapping all memory in MTRRs. There are only two corrections I would like to make to Davids eMail: > # cat >/proc/mtrr > disable=2 > disable=3 > disable=4 > disab

Not MTRR !? was: ISSUE: very slow (factor 100) 4-way 16GByte server, with 2.4.2

Hello everyone. As far as I can see almost all memory is set write-back. The memory at the far end belongs to some hardware, see /proc/iomem below. Are there any other suggestions why our machine is so slow, or perhaps 'write-back' is the reason??? If You need more info, please tell me, I wil

ISSUE: very slow (factor 100) 4-way 16GByte server, with 2.4.2

Hello, ISSUE: very slow (factor 100) 4-way 16GByte server, with 2.4.2 DESCR: we have a Maxdata 4-way Xeon, with 16GByte RAM. If we compile a kernel (2.4.0 or 2.4.2 up to ac25) that uses all 16 GByte RAM the machine gets very slow. For example network Bandwidth of 100MBit Ethernet is about 1-50k