DMA problem (?) w/ 2.4.6-xfs and ServerWorks OSB4 Chipset
The latest RH kernel, 2.4.3-12, works ok for us if we recompile with the explicit OSB4 support disabled and turn on UDMA2 manually with hdparm. The system stands up to continuous pounding with Bonnie and benchmarks at
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20MB/sec for block reads (Tyan 2515). On the other hand, with the OSB4
support turned on we see DMA timeouts immediately. I've just started some tests with OSB4 turned on in 2.4.7-ac2 and so far it seems ok.
On an unrelated topic the Serverworks LE chipset does not seem to be capable of handling 4GB of RAM, despite what the board vendors claim in their specs. When a 4th 1G stick is added the system gets really slow --- like maybe cacheing is disabled. We've seen this on both Tyan and SuperMicro boards. The HE chipset seems to be ok.
Marvin Justice
Quoted 7 lines · Marvin Justice
On an unrelated topic the Serverworks LE chipset does not seem to be capable of handling 4GB of RAM, despite what the board vendors claim in their specs. When a 4th 1G stick is added the system gets really slow --- like maybe cacheing is disabled. We've seen this on both Tyan and SuperMicro boards. The HE chipset seems to be ok.
Marvin Justice
I believe I remember a thread some time ago regarding the fact that sometimes caching only works for a certain maximum amount of memory. It could very well be that this is the case.
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Ignacio Vazquez-Abrams <[email protected]>
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On an unrelated topic the Serverworks LE chipset does not seem to be capable of handling 4GB of RAM, despite what the board vendors claim in their specs. When a 4th 1G stick is added the system gets really slow --- like maybe cacheing is disabled. We've seen this on both Tyan and SuperMicro boards. The HE chipset seems to be ok.
Check the mtrr setups. I've seen slow machines that are slow with 4Gb purely because the bios misconfigured the memory type ranges
Alan