Re: Resets on sil3124 & sil3726 PMP

[Petr Vandrovec <vandrove@vc.cvut.cz>]

Tejun Heo wrote:
> Petr Vandrovec wrote:
>> For comparsion 1TB Hitachi behind 3726 PMP (again MS4UM) with sata_sil
>> patch I sent last week (no NCQ, 1.5Gbps link between 3512 and PMP, and
>> 3.0Gbps link between PMP and drive... why is it faster?):
> 
> If you turn off NCQ by echoing 1 to /sys/block/sdd/device/queue_depth on
> sata_sil24, does the performance change?

I have recompiled kernel with all debugging disabled, and it brought me 
1.5MBps, so it is still consistently 1MBps slower than on sil. 
Disabling NCQ seems to improve concurrent access a bit (for which I have 
no explanation), while slows down single drive scenario:

With NCQ:

1TB alone: 81.22, 79.86
1TB+1TB:   56.28+56.70, 53.51+56.11

Without NCQ:

1TB alone: 79.78, 80.82
1TB+1TB:   57.99+58.12, 56.50+56.46

3512 sil, no NCQ:

1TB alone: 82.28, 82.18
1TB+1TB:   47.20+47.54    # Here apparently command based switching or 
1.5Gbps link between device and PMP becomes bottleneck

And it seems that I observe what other poster pointed out - that 
apparently all SiI chips are limited somewhere around 120-130MBps, and 
cannot do more even if you pretty ask...
							Petr