UC/USWC i bios

[bazzo]

I bios står det noe om "Video Memory Cache Mode" (UC)

Her kan jeg velge mellom "UC" eller "USWC",

hva er forskjellen på disse?

[bazzo]

ingen så vet ???

[MistaPi]

Enabling USWC allows several small writes to be buffered up and sent to AGP as one write. Since graphics data tends to have very strong locality, this increases the throughput of the bus and unloads the processor to some extent. But it also increases the latency of the small writes and can cause slowdowns when the writes are more random... as always it's a tradeoff that must be made based on benchmarking your typical workloads.

 

This extra latency that you get when enabling USWC can work for you on a high OC by allowing the AGP card more time between writes. It's possible that by performing the writes immediately in UC mode, wait times between writes were too short because the bus was clocked so far out of spec. Same principle as increasing the memory timings for high OCs.