View previous topic :: View next topic |
Author |
Message |
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Mon Jun 04, 2012 3:44 pm Post subject: Ocz agility3 low speed (SSD) |
|
|
Hello ,
these are the results/infos i took from terminal
hdparm -Tt /dev/sdb
Code: |
/dev/sdb:
Timing cached reads: 7420 MB in 2.00 seconds = 3711.45 MB/sec
Timing buffered disk reads: 500 MB in 3.01 seconds = 165.85 MB/sec |
it have to be like this
Code: | Timing cached reads: 27738 MB in 2.00 seconds = 13889.38 MB/sec
Timing buffered disk reads: 1158 MB in 3.01 seconds =385.08 MB/sec |
Why?How can i solve it?
The disk is like a normal.
I am waiting for your help
thank you |
|
Back to top |
|
|
whiteghost Guru
Joined: 26 Jul 2009 Posts: 374 Location: north dakota
|
Posted: Mon Jun 04, 2012 6:45 pm Post subject: |
|
|
from my agility 2 60G
Code: | # hdparm -Tt /dev/sda
/dev/sda:
Timing cached reads: 7528 MB in 2.00 seconds = 3764.76 MB/sec
Timing buffered disk reads: 638 MB in 3.01 seconds = 212.20 MB/sec
|
Quote: | Timing cached reads: 27738 MB in 2.00 seconds = 13889.38 MB/sec
Timing buffered disk reads: 1158 MB in 3.01 seconds =385.08 MB/sec |
sounds ridiculous to me _________________ www.informationclearinghouse.info
May you re-discover what the poor in 18th century France discovered, that rich people's heads can be mechanically separated from their shoulders if they refuse to listen to reason. |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Thu Jun 07, 2012 4:19 pm Post subject: |
|
|
Any help please?
@whiteghost
PostPosted: Mon Jun 04, 2012 6:45 pm Post subject:
from my agility 2 60G
Code:
# hdparm -Tt /dev/sda
/dev/sda:
Timing cached reads: 7528 MB in 2.00 seconds = 3764.76 MB/sec
Timing buffered disk reads: 638 MB in 3.01 seconds = 212.20 MB/sec
so you are faster than me and you have agility 2! |
|
Back to top |
|
|
WorBlux n00b
Joined: 07 May 2011 Posts: 39
|
Posted: Thu Jun 07, 2012 5:19 pm Post subject: |
|
|
Just curious, what sort of motherboard do you have? |
|
Back to top |
|
|
whiteghost Guru
Joined: 26 Jul 2009 Posts: 374 Location: north dakota
|
Posted: Thu Jun 07, 2012 7:34 pm Post subject: |
|
|
do you have a sata 3 connection?
i've never seen anyone match the benchmark posted at archlinux forum, so i am skeptical.
i use a desktop and have lots of memory and hdd.
so i mount /var/tmp/portage and /tmp tmpfs in fstab.
i make my distfiles directory /distfiles and mount on a hdd.
i used to not use swap but have recently made swap on hdd.
i use gparted to partition and it has option to align to MiB
use ahci driver and try not to fill over 70 %
http://www.ocztechnologyforum.com/forum/showthread.php?97693-is-certain-amount-of-free-space-required-for-optimal-performance
that is about all you can do.
while i have gone to lengths to avoid writes a person also should not be afraid to use their ssd. it should last a long time. _________________ www.informationclearinghouse.info
May you re-discover what the poor in 18th century France discovered, that rich people's heads can be mechanically separated from their shoulders if they refuse to listen to reason. |
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Fri Jun 08, 2012 12:28 am Post subject: |
|
|
Not same machine or disk, but numbers are very possible... but machine dependent.
Code: | Timing cached reads: 29206 MB in 2.00 seconds = 14624.82 MB/sec
Timing buffered disk reads: 1128 MB in 3.00 seconds = 375.98 MB/sec |
Not using the same disk, but still SSD: Core i7/z68/SSD520
Yes, SATA3 (6Gb/sec) is needed to get this high... Make sure you're using a good cable and a SATA3 port. There's only 2 on my z68 board... _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
whiteghost Guru
Joined: 26 Jul 2009 Posts: 374 Location: north dakota
|
Posted: Fri Jun 08, 2012 2:27 am Post subject: |
|
|
eccerr0r wrote: | Not same machine or disk, but numbers are very possible... but machine dependent.
Code: | Timing cached reads: 29206 MB in 2.00 seconds = 14624.82 MB/sec
Timing buffered disk reads: 1128 MB in 3.00 seconds = 375.98 MB/sec |
Not using the same disk, but still SSD: Core i7/z68/SSD520
Yes, SATA3 (6Gb/sec) is needed to get this high... Make sure you're using a good cable and a SATA3 port. There's only 2 on my z68 board... |
i looked at the specs for agility 3 and intel 520 at newegg, very close. _________________ www.informationclearinghouse.info
May you re-discover what the poor in 18th century France discovered, that rich people's heads can be mechanically separated from their shoulders if they refuse to listen to reason. |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Sun Jun 10, 2012 4:32 pm Post subject: |
|
|
my specs
AMD Phenom(tm) II X4 955 Processor
ASRock 890GM Pro3 R2.0
6gb ddr3 1600 ram
i think <<good>> sata cable and sata 3 port..
and the disk has 35% available space |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Tue Jun 19, 2012 12:59 pm Post subject: |
|
|
So any help please?Whats the error-problem? |
|
Back to top |
|
|
steffie n00b
Joined: 11 May 2012 Posts: 4
|
Posted: Tue Jun 19, 2012 2:28 pm Post subject: |
|
|
gentoorockerfr wrote: | So any help please?Whats the error-problem? |
ASRock Z68 Pro3-M, SAMSUNG 470 64.0GB
hdparm -Tt /dev/sda
/dev/sda:
Timing cached reads: 20418 MB in 2.00 seconds = 10220.55 MB/sec
Timing buffered disk reads: 706 MB in 3.00 seconds = 234.96 MB/sec
PCI bridge: ASMedia Technology Inc. ASM1083/1085 PCIe to PCI Bridge |
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Tue Jun 19, 2012 3:12 pm Post subject: |
|
|
I do have to say something is strange - how old is the AsRock 890GM board?
It's weird that it has 5 SATA 6Gb ports but my Z68 (Gigabyte Z68AP-D3) only has two... Apparently Intel thinks sata 6Gb ports are hard to attach and therefore only offers 2... Not sure if it's the motherboard limiting the speed or not.
How are the SATA6Gb attached to the cpu, does it go through the southbridge (bad)? When you're using hdparm to test, it should not care about fragmentation much, as fragmentation really affects small writes.
steffie: what CPU do you have? Curious how much the CPU determines the cached read speeds versus the chipset/disk... _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Tue Jun 19, 2012 3:31 pm Post subject: |
|
|
My motherboard is this
http://www.asrock.com/mb/overview.asp?model=890gm%20pro3%20r2.0
How are the SATA6Gb attached to the cpu, does it go through the southbridge (bad)? When you're using hdparm to test, it should not care about fragmentation much, as fragmentation really affects small writes.
could you explain it? |
|
Back to top |
|
|
Naib Watchman
Joined: 21 May 2004 Posts: 6051 Location: Removed by Neddy
|
Posted: Tue Jun 19, 2012 4:02 pm Post subject: |
|
|
When you partitioned the drive did you ensure it was aligned to 4k as oppose to 512?
by default fdisk will partition assuming a 512b sector size, which is valid for old HDD
Newer HDD as well as SSD have sector sizes of 4096 (so they don't run out of indexing). Thing is if you partition the drive without taking this into consideration and the partition/s are NOT aligned to these clusters you end up in a situation where reads/writes require spanning 2 sectors to complete resulting in additional commands being issued to the controller _________________
Quote: | Removed by Chiitoo |
|
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Tue Jun 19, 2012 5:25 pm Post subject: |
|
|
Code: | fdisk /dev/sdb1
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xd52ef117.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) |
Code: |
fdisk -lu /dev/sdb
Disk /dev/sdb: 60.0 GB, 60022480896 bytes
255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000550b3
Device Boot Start End Blocks Id System
/dev/sdb1 2048 117229567 58613760 83 Linux |
So whats my next move? |
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Tue Jun 19, 2012 9:13 pm Post subject: |
|
|
The port connection issue is very technical but it boils down to the latency and bottlenecks involved when passing data through the channels. Now I don't know too much about AMD Hypertransport unfortunately, only have some rudimentary knowledge about Intel QPI, but I have to assume they have some similarities. The SATA controllers can be connected to the first level QPI where bandwidths are highest but there are a limited number of connections. One possibility to increase the number of connections is to put it on a bridge to multiplex more connections, usually the southbridge. There's latency and delays involved there which will slow down throughput.
The sector fragmentation is an interesting possibility but if you hdparm on the raw device like /dev/sda, etc., this should be aligned to the first sector/sector 0, which should be aligned to any sector size, or at least I would hope it to be the case... With newer versions of fdisk starting at sector 2048 this should be aligned to 4096 byte-sectors as long as your partitions are a multiple of 4096 bytes. _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Wed Jun 20, 2012 11:25 am Post subject: |
|
|
can i change alignment to 4k without delete/format the disk?
ps so the problem exist because disk's alignment?512b instead of 4k? |
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Wed Jun 20, 2012 1:08 pm Post subject: |
|
|
I think it already is, but you can't really redo without erasing everything (though gparted might be able to do something).
Start sector 2048 (versus 63, because old versions of fdisk aligned to "track" which makes sense for very old disks) is a multiple of 4096 since 2048*512 is a multiple of 4096 - it's the 256th 4096 sector.
I'm still convinced it's a motherboard issue at the moment. _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Wed Jun 20, 2012 4:47 pm Post subject: |
|
|
could you tell me please how to format a ssd disk to have full performance.What about gptfdisk?
Also what these lines said?
255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
ps how could i overtake motheboard issue? |
|
Back to top |
|
|
Naib Watchman
Joined: 21 May 2004 Posts: 6051 Location: Removed by Neddy
|
Posted: Wed Jun 20, 2012 7:20 pm Post subject: |
|
|
Code: |
fdisk -lu /dev/sdb
Disk /dev/sdb: 60.0 GB, 60022480896 bytes
255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000550b3
Device Boot Start End Blocks Id System
/dev/sdb1 2048 117229567 58613760 83 Linux |
See that looks like 512b blocksize.
cat /sys/block/sda/queue/physical_block_size
4096
cat /sys/block/sda/queue/logical_block_size
512 _________________
Quote: | Removed by Chiitoo |
|
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Wed Jun 20, 2012 8:39 pm Post subject: |
|
|
yes...
Code: | cat /sys/block/sda/queue/physical_block_size
512
cat /sys/block/sda/queue/logical_block_size
512 |
why..
i think that i partioned this disk with gparted...
could you tell me please how to format a ssd disk to have full performance.What about gptfdisk?
whats next move?
thank you for your time |
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Thu Jun 21, 2012 12:47 am Post subject: |
|
|
Motherboard issue meaning: replace motherboard with another brand and/or newer chipset that has the SATA ports attached differently to hypertransport.
This is if you're sure you're using the correct driver for the SATA chipset.
Granted I don't know enough about AMD bus structures and chipsets (other than the fact that my AthlonXP + SiS and AthlonXP + nVidia chipset systems seem a little slow to PATA IDE cache), but the Intel Z68 seems to do fine... _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
gentoorockerfr Apprentice
Joined: 25 May 2012 Posts: 203
|
Posted: Sun Jun 24, 2012 5:55 pm Post subject: |
|
|
so there is not any problem because of 512b alignment of my ssd? |
|
Back to top |
|
|
Naib Watchman
Joined: 21 May 2004 Posts: 6051 Location: Removed by Neddy
|
|
Back to top |
|
|
eccerr0r Watchman
Joined: 01 Jul 2004 Posts: 9679 Location: almost Mile High in the USA
|
Posted: Wed Jun 27, 2012 1:28 pm Post subject: |
|
|
Imagine if hard drives "Bus Errors" when someone does an unaligned access...
(sorry about this bad, obscure joke related to how some CPUs will bus error when doing unaligned accesses. Once again this is a performance related issue on CPUs too! Then again the bus errors were meant to make people rewrite their code, maybe we need to do this for HDDs too...) _________________ Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching? |
|
Back to top |
|
|
|