Messages in this thread | | | From | Marco Colombo <> | Subject | Re: disk transfer speed problem |
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On Thu, 28 Feb 2002, lonely wolf wrote: > Mark Hahn wrote: [...] > > well, 109 MB/s is pretty low for buffer-cache reads; this reflects > > the relative crippled-ness of your cpu/dram/chipset. > > well... i would't name a Celeron 900 MHz crippled. PC133 is the best the > board gets... and now the speed is lower then the previous server which was > an Athlon 600 pluggede in an Asus VIA KX133 based mobo.
I don't really see why you're expecting a performance breakthru downgrading from Athlon to Celeron... many all-in-one MB (targeted to Celeron system) are somewhat crippled and CPU MHz mean close to nothing for I/O performance (or performance in general - read some papers explaining that on 200MHz PentiumPro systems the bottleneck was RAM bandwidth!)
The buffer-cache reads timing (Mark was referring to) is sometimes a good index:
Timing buffer-cache reads: 128 MB in 0.80 seconds =160.00 MB/sec Timing buffered disk reads: 64 MB in 1.79 seconds = 35.75 MB/sec
(Athlon 700 slot-A system, not idle. I've seen 165+. Also note disk b/w.)
Timing buffer-cache reads: 128 MB in 0.58 seconds =220.69 MB/sec Timing buffered disk reads: 64 MB in 1.85 seconds = 34.59 MB/sec
(Athlon 1333 DDR system, not idle. On initlevel 1 I've seen 245+)
Now, 220 vs 109 is a lot. But even 160 vs 109 is. Even the slowest system I've seen (Duron 700MHz) was above 140. I bet your old Althon system was capable of at least 145/150. So you downgraded, that's all.
rule 1: don't buy MB with integrated (shared mem) video chips; rule 2: use DDR capable MB and CPU, @ 133MHz (or 266 on ad material); rule 3: use SCSI if you can afford it. But ATA is fine on low-end.
> > > doesn't the i815 have integrated video, > > yes > > > and if so, are you using it, > > yes > > > and if so, do you have the optional "display cache"? > > couldn't find any BIOS setting for that. where should it be ? > > > without the DC, video steals quite a lot of dram bandwidth... > > the machine is (should be) a NFS server, I couldn't care less about the > video
it manages to steal mem b/w anyway.
Don't use that MB (and Celerons) for servers.
.TM. -- ____/ ____/ / / / / Marco Colombo ___/ ___ / / Technical Manager / / / ESI s.r.l. _____/ _____/ _/ Colombo@ESI.it
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