Re: SSD write speed issues

[Paul Goyette <paul%whooppee.com@localhost>]

Did you start the C partition at block 63?  Try starting at block 
2048...

If the SSD has a native blocksize bigger than 512 bytes, you're doing a 
lot of read-modify-write cycles.


On Fri, 1 Aug 2014, Zafer AydoÄ~_an wrote:

> Hello List,
>
> I am experiencing slow write speeds with a new server using an SSD drive.
> I'm running the latest current 6.99.49 (amd64) and I'm getting
> only about 8 MB/s write speed. I'm expecting > 300 MB/s of write speed.
>
> The relevant parts of the dmesg:
>
> pci0 at mainbus0 bus 0: configuration mode 1
> pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
>
> ahcisata0 at pci0 dev 17 function 0: vendor 0x1022 product 0x7801 (rev. 0x40)
> ahcisata0: interrupting at ioapic0 pin 19
> ahcisata0: 64-bit DMA
> ahcisata0: AHCI revision 1.30, 1 port, 32 slots, CAP
> 0xf733ff00<PSC,SSC,PMD,FBSS,SPM,ISS=0x3=Gen3,SCLO,SAL,SALP,SMPS,SSNTF,SNCQ,S64A>
> atabus0 at ahcisata0 channel 0
>
> ahcisata0 port 0: device present, speed: 6.0Gb/s
> wd0 at atabus0 drive 0
> wd0: <SanDisk SSD i110 32GB>
> wd0: drive supports 1-sector PIO transfers, LBA48 addressing
> wd0: 30533 MB, 62037 cyl, 16 head, 63 sec, 512 bytes/sect x 62533296 sectors
> wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)
> wd0(ahcisata0:0:0): using PIO mode 4, DMA mode 2, Ultra-DMA mode 6
> (Ultra/133) (using DMA)
>
>
> Any ideas ?
>
>
> Cheers,
> Zafer

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