Hard drives with 4kb sector-size are now available

[rloew]

Has anyone tested the performance of 4K drives with aligned partitions on Win9x? Is there performance degradation?

Even if the data area is 4K aligned and uses 4K clusters, wouldn't there be degraded performance on FAT accesses (which aren't cluster-bound)?

Windows 9x implements 4KiB transfers internally whenever possible. This was done to improve performance and to reduce Memory paging issues. If the Data Clusters are at least 4KiB and aligned on physical 4KiB Sector boundaries, there will be no degradation. This alignment applies to the Data area, not the Partition itself.

[jaclaz]

Windows 9x implements 4KiB transfers internally whenever possible. This was done to improve performance and to reduce Memory paging issues. If the Data Clusters are at least 4KiB and aligned on physical 4KiB Sector boundaries, there will be no degradation. This alignment applies to the Data area, not the Partition itself.

Yep.

We have here the result of a test, that, though made on NT based system, may give an idea both of the procedure and of the advantages:

jaclaz

[osRe]

Windows 9x implements 4KiB transfers internally whenever possible. This was done to improve performance and to reduce Memory paging issues. If the Data Clusters are at least 4KiB and aligned on physical 4KiB Sector boundaries, there will be no degradation. This alignment applies to the Data area, not the Partition itself.

But what about when reading/writing cluster chains in the FAT itself?

The surest way to tell would be to benchmark it, but I don't have 4K drives, and I'll try to avoid them for now, if I can.

[rloew]

Windows 9x implements 4KiB transfers internally whenever possible. This was done to improve performance and to reduce Memory paging issues. If the Data Clusters are at least 4KiB and aligned on physical 4KiB Sector boundaries, there will be no degradation. This alignment applies to the Data area, not the Partition itself.

But what about when reading/writing cluster chains in the FAT itself?

The surest way to tell would be to benchmark it, but I don't have 4K drives, and I'll try to avoid them for now, if I can.

Windows 9x does the same buffering on the FAT itself so large requests will still be aligned. Most reading and writing of the FAT would be one sector at a time though, so alignment would have no significance.

[osRe]

That's good news. So it seems quite possible that a properly aligned partition with the right reserved area size would work well.

I don't remember now the exact structure of things, but wouldn't the cluster count need to to be set to specific values because the 2nd FAT copy would go right after the first, so may be unaligned?

[jaclaz]

That's good news. So it seems quite possible that a properly aligned partition with the right reserved area size would work well.

I don't remember now the exact structure of things, but wouldn't the cluster count need to to be set to specific values because the 2nd FAT copy would go right after the first, so may be unaligned?

Yes, if you read the already given thread:

and this one:

You may get some ideas/data/methods/tools.

jaclaz

[jds]

IO.SYS needs patches to increase some buffers to handle the larger Sectors and to recognize the Sector Length field in the Boot Sector's BPB.

What is the native capability of IO.SYS, 512 bytes or 2K bytes? (The last part of that comment at least, implies 512 bytes.)

BTW, I just purchased a cheap MP3/MP4 player whose sector size (via USB) is 1KB. I'm having some difficulties with it (in all O/S, from DOS to Vista), but that may be due to the quality (or lack thereof) of its Flash, rather than its sector size. It's formatted as a "Super Floppy" (sans MBR). Anyway, that's what led me to re-read this thread.

Joe.

[rloew]

IO.SYS needs patches to increase some buffers to handle the larger Sectors and to recognize the Sector Length field in the Boot Sector's BPB.

What is the native capability of IO.SYS, 512 bytes or 2K bytes? (The last part of that comment at least, implies 512 bytes.)

BTW, I just purchased a cheap MP3/MP4 player whose sector size (via USB) is 1KB. I'm having some difficulties with it (in all O/S, from DOS to Vista), but that may be due to the quality (or lack thereof) of its Flash, rather than its sector size. It's formatted as a "Super Floppy" (sans MBR). Anyway, that's what led me to re-read this thread.

Joe.

As is, DOS and Windows 9x will only handle 512 Byte Sectors. I have extended DOS to 32KiB and Windows 98 and 98SE to 4KiB.