Anonymous Coward
Veteran Member
I have been trying to optimise my old 486 VLB systems for disk performance, and I find this to be the most challenging aspects of the PC to improve on.
The VL Bus is capable of something between 32MB - 132MB/sec (depending on the configuration). The fastest VLB controllers I know of are EIDE PIO Mode4. I have some that claim to be "PIO5" using DMA, but I haven't gotten that working yet. I have three controllers. A Promise, a QDI and a DTC. PIO4 is supposed to do 16MB/sec. However, I am not able to get performance anywhere near this using modern 7200 EIDE drives that I know are capable of very high transfer rates. The best I can do for average transfer rates is about 7MB/sec. Peak is maybe around 11MB/sec. I have heard of people claiming 11MB/sec average transfer rates on VLB, but I really wonder how they do this. As you know, configuring the VLB controllers can be challenging. There are many settings in the BIOS, DOS and Windows drivers to take into consideration. I am wondering if anyone has a good procedure for squeezing out as much as they can from their VLB controllers.
The VL Bus is capable of something between 32MB - 132MB/sec (depending on the configuration). The fastest VLB controllers I know of are EIDE PIO Mode4. I have some that claim to be "PIO5" using DMA, but I haven't gotten that working yet. I have three controllers. A Promise, a QDI and a DTC. PIO4 is supposed to do 16MB/sec. However, I am not able to get performance anywhere near this using modern 7200 EIDE drives that I know are capable of very high transfer rates. The best I can do for average transfer rates is about 7MB/sec. Peak is maybe around 11MB/sec. I have heard of people claiming 11MB/sec average transfer rates on VLB, but I really wonder how they do this. As you know, configuring the VLB controllers can be challenging. There are many settings in the BIOS, DOS and Windows drivers to take into consideration. I am wondering if anyone has a good procedure for squeezing out as much as they can from their VLB controllers.