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#1 2012-11-01 18:25:54

Valvar
Member
Registered: 2012-11-01
Posts: 15

Samsung SSD 830 running at SATA2 speeds

I recently purchased a 256gb samsung 830 SSD. It's plugged into a SATA3 port, bios settings are correct (I tried lots of different combinations anyway), I followed the directions given here, the cable is the one that came with the mobo and the southbridge is definitely not overloaded.

Here are my benchmarks:

# hdparm -Tt /dev/sda
/dev/sda:
 Timing cached reads:   4194 MB in  2.00 seconds = 2097.01 MB/sec
 Timing buffered disk reads: 732 MB in  3.01 seconds = 243.35 MB/sec
dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 3.05939 s, 351 MB/s
# echo 3 > /proc/sys/vm/drop_caches
# dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 2.20608 s, 487 MB/s
dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.449711 s, 2.4 GB/s

Compared to these benchmarks for the same drive, you can see that it's not keeping up.

Here's my specs in case it helps:

# inxi -F
System:    Host: skynet Kernel: 3.6.3-1-ARCH x86_64 (64 bit) Desktop: KDE 4.9.2 Distro: Arch Linux
Machine:   Mobo: Gigabyte model: GA-890GPA-UD3H Bios: Award version: FD date: 07/23/2010
CPU:       Quad core AMD Athlon II X4 645 (-MCP-) cache: 2048 KB flags: (lm nx sse sse2 sse3 sse4a svm) 
           Clock Speeds: 1: 800.00 MHz 2: 800.00 MHz 3: 800.00 MHz 4: 800.00 MHz
Graphics:  Card: NVIDIA GF100 [GeForce GTX 480] X.org: 1.13.0 driver: nvidia tty size: 176x41 Advanced Data: N/A for root 
Audio:     Card-1: NVIDIA GF100 High Definition Audio Controller driver: snd_hda_intel Sound: ALSA ver: 1.0.25
           Card-2: Advanced Micro Devices [AMD] nee ATI SBx00 Azalia (Intel HDA) driver: snd_hda_intel 
Network:   Card-1: Realtek RTL-8185 IEEE 802.11a/b/g Wireless LAN Controller driver: rtl8180 
           IF: wlan0 state: down mac: 00:e0:46:10:01:d9
           Card-2: Realtek RTL8111/8168B PCI Express Gigabit Ethernet controller driver: r8169 
           IF: eth0 state: up speed: 100 Mbps duplex: full mac: 1c:6f:65:37:95:bd
Drives:    HDD Total Size: 3256.6GB (36.2% used) 1: id: /dev/sda model: SAMSUNG_SSD_830 size: 256.1GB 
           2: id: /dev/sdb model: GoFlex_Desk size: 3000.6GB 
Partition: ID: / size: 235G used: 51G (23%) fs: ext4 
Sensors:   System Temperatures: cpu: 35.5C mobo: N/A gpu: 67C 
           Fan Speeds (in rpm): cpu: N/A 
Info:      Processes: 158 Uptime: 2:22 Memory: 1100.6/7988.2MB Client: Shell inxi: 1.8.20

What can I do about this? Any help is appreciated.

Last edited by Valvar (2012-11-01 18:28:25)

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#2 2012-11-01 18:28:26

WonderWoofy
Member
From: Los Gatos, CA
Registered: 2012-05-19
Posts: 8,412

Re: Samsung SSD 830 running at SATA2 speeds

There are a number of factors that can influence the speed of an SSD.  So simply specifying your SSD along and no other mention of harware (besides that it is connected to a SATAIII port) is probably nto enough information to really get you anywhere with this question.

Edit: BTW, I dind't know that page existed... I also didn't realize how much my Kingston Hyper 3k kicks some ass.  Also, my Mushkin mSATA Atlas 120GB does pretty damn well for being on a SATA II port.  I'll have to do the tests a couple more times in order to get an average to contribute.  But inital test went quite well.

Last edited by WonderWoofy (2012-11-01 18:50:46)

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#3 2012-11-01 18:28:54

Valvar
Member
Registered: 2012-11-01
Posts: 15

Re: Samsung SSD 830 running at SATA2 speeds

Sorry, I edited my post and added my hardware info.

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#4 2012-11-02 15:12:05

technolog
Member
From: Europe / Slovenia / Grosuplje
Registered: 2012-01-28
Posts: 116

Re: Samsung SSD 830 running at SATA2 speeds

These are clearly SATA 3 speeds, because practical speeds with SATA 2 do not exceed 270 MiB/s.

I'd run fstrim on the device. That should improve the result.

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#5 2012-11-03 10:49:38

Stalafin
Member
From: Berlin, Germany
Registered: 2007-10-26
Posts: 616

Re: Samsung SSD 830 running at SATA2 speeds

technolog wrote:

These are clearly SATA 3 speeds, because practical speeds with SATA 2 do not exceed 270 MiB/s.

I'd run fstrim on the device. That should improve the result.

Make a daily or weekly cronjob for fstrim! smile

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#6 2012-11-05 06:29:19

celf
Member
From: Espoo / Finland
Registered: 2004-09-15
Posts: 15

Re: Samsung SSD 830 running at SATA2 speeds

Maybe partition alignment?

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#7 2012-11-05 06:45:56

WonderWoofy
Member
From: Los Gatos, CA
Registered: 2012-05-19
Posts: 8,412

Re: Samsung SSD 830 running at SATA2 speeds

@Stalafin, out of curiosity, do you prefer to use a fstrim cronjob rather than mouting with discard?  I ask because I just always mount with discard, but recently I read that this can slightly degrade fielsystem performance while offering very little benefit with improved garbage collection by newer ssd's.

BTW, @OP, I just got a Samsung 830 and it is pretty awesome.  Not actually using it yet, but I tested it out, and I like it.  I think your speeds are definitely SATA III, as technolog pointed out, they are faster than the capabilities of SATA II.  I didn't run these tests on the 830, so I don't know how mine would have compared.

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#8 2012-11-05 16:10:52

Valvar
Member
Registered: 2012-11-01
Posts: 15

Re: Samsung SSD 830 running at SATA2 speeds

Thanks guys. fstrim definitely improved the performance. Not quite at the benchmarks I've seen from others, but not too shabby now.

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