Date: Fri, 10 Jan 1997 02:11:48 +1030 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: M.S.Powell@ais.salford.ac.uk (Mark Powell) Cc: msmith@atrad.adelaide.edu.au, freebsd-scsi@freebsd.org, freebsd-scsifreeb@sdorgsd.org Subject: Re: Can the P/I-P55T2P4 be overclocked? In other words does it support 75 and 83MHz bus speeds? Message-ID: <199701091541.CAA27446@genesis.atrad.adelaide.edu.au> In-Reply-To: <Pine.BSF.3.95.970109150900.21964A-100000@plato.salford.ac.uk> from Mark Powell at "Jan 9, 97 03:20:06 pm"
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Mark Powell stands accused of saying: > > Yeah, I know. I meant if the 875 wasn't supported I could use the 810 with > narrow drives and still push the external clock speed to 75MHz. However, That would be stupid. The extra CPU performance would be more than offset by the loss of disk performance in all but the most extreme cases. > now you've enlightened me I can get the 875 and use it under FreeBSD with > my wide drives and hopefully with a greater chance of success than with a > 7880. If you have several wide disks, the 7880 will probably give better performance than the 875, all other things being equal. > These chipsets are designed to accomodate the Cyrix P200+ which needs an > external clock speed of 75MHz. They also support the Cyrix's "Linear Burst > Mode" which can supposedly give a 3-5% speed improvement on cache filling. > However, I agree and think I'd be going down a blind alley with such new > chipsets. I'll stick with the 430HX chipset on the T2P4. No! You're not paying attention 8) You want an _FX_ chipset motherboard, specifically for the improved CPU-memory bandwidth. Even the VX with all its corners cut is faster than the HX. Don't kid yourself that the extra few MHz of PCI speed will make major differences to your performance, particularly if it means that you sacrifice CPU-memory bandwidth to get it. Spend some time looking for the real bottlenecks in the system rather than trying to open paths that are already adequately wide. > Mark Powell - Unix Information Officer - Clifford Whitworth Building -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[
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