Low serdes SATA speed

[immbalu]

Hello All,

We have Using T4241 with SERDES4 Protocol: 9 (0x9) and WD Blue 500GB 2.5 SATA SSD is connected to processor.

We are trying to copy data to SATA but can able to achieve only 500Mbps when large data is being transferred. As per processor it supports 3Gbps. When the small amount of data (1GB) is copied i'm able to get desired throughput. When data to transfer is more (greater then 10GB) then only 500Mbps speed achieved. How do i increase the data rate?

Regards,

Balaji.G

[yipingwang]

Could you please share your test log?

[immbalu]

Hello, 

Please find the logs,

root@t4240rdb:~# dd if=/dev/zero of=/run/media/sda/speetest bs=512K count=10240 ;rm run/media/sda/speetest
10240+0 records in
10240+0 records out
5368709120 bytes (5.0GB) copied, 52.527123 seconds, 97.5MB/s

root@t4240rdb:~# dd if=/dev/zero of=/run/media/sda/speetest bs=1M count=25600
25600+0 records in
25600+0 records out
26843545600 bytes (25.0GB) copied, 370.058443 seconds, 69.2MB/s

Regards,

Balaji.G

[yipingwang]

DD command can't be used for performance test.

I had a test by iozone command shows the write speed is about 200MB/s.
The log is as follows:

Excel chart generation enabled
Auto Mode
Using minimum file size of 31457280 kilobytes.
Using maximum file size of 31457280 kilobytes.
Record Size 64 kB
Command line used: iozone -Rab /mnt/sata/result0.xls -i 0 -i 1 -f /mnt/sata/test -n 30G -g 30G -r 64k
Output is in kBytes/sec
Time Resolution = 0.000001 seconds.
Processor cache size set to 1024 kBytes.
Processor cache line size set to 32 bytes.
File stride size set to 17 * record size.
random random bkwd record stride
kB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
31457280 64 199407 203691 193875 193823

iozone test complete.
Excel output is below:

"Writer report"
"64"
"31457280" 199407

"Re-writer report"
"64"
"31457280" 203691

"Reader report"
"64"
"31457280" 193875

"Re-Reader report"
"64"
"31457280" 193823