Re: kernels and b0xen
On 24 Jan, this message from simon@nuit.ca echoed through cyberspace:
>> > > BTW, I get 45 MB/s for the buffer-cache on my 66 MHz SDRAM.
>> >
>> > Looks still very low, very conservative bridge timings? This means a
>> > cache line read (32 bytes) every 700ns or so. Even if you dirty every
>> > cache line, doubling the traffic, this means 350ns per burst transfer.
>>
>> Note these are the results of `hdparm -T', not from a real memory benchmark.
>> Real memory read performance is ca. 100 MB/s, which is reasonable for machines
>> of that age, cfr. http://home.tvd.be/cr26864/Linux/PPC/MemSpeed.html
>
> hm, well other than the cache on the CPU and the RAM and disk caches, i
> don't have a cache per se, i.e., on mobo L2 cache. this could be making
> a rather large difference. i didn't realise that until now.
This is with a 604 processor, right? Then yes, you should try to get a
cheap cache DIMM from Ebay. For the 7x00/8x00 machines cache increased
performance by up to 20%.
Cheers
Michel
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