From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nigel Roles" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: RE: [9fans] nvidia scrolling performance Date: Mon, 1 May 2006 07:52:43 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit In-Reply-To: <44553B66.5010604@lanl.gov> Topicbox-Message-UUID: 4c03baee-ead1-11e9-9d60-3106f5b1d025 9fans-bounces+ngr=9fs.org@cse.psu.edu wrote: > Steve Simon wrote: > >> I may be talking rubbish but I understood this is a fundamental >> problem with reading VGA memory over the PCI bus. VGA cards are >> designed for fast writes and not fast reads. > > depends. > > on pci and AGP it's an issue. > AGP has the assymetric bandwidth built in. > > on PCI express, it's supposed to get much better. > > >> I do hear that some cards are appearing with dual PCIX which will >> allow symetric access speeds to the frame buffer. >> > > Note that PCIX is not pci express (PCIe or PCI-e or PCI-E). It's so > confusing. PCIX is PCI-X which is an old, slow bus. > > ron PCIX is slow? Is 34Gbps not quick enough for you?