FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Gentoo > Gentoo User

 
 
LinkBack Thread Tools
 
Old 08-22-2012, 09:46 PM
Mark Knecht
 
Default SSD performance tweaking

Hi,
Yesterday I got a new, but rather low-end, PCIe-2 SATA-3 6Gb/S
adapter card and a reportedly high performance 128GB SSD drive. (Links
below) Other than my swap getting messed up because it didn't use
labels (who knew about swaplabel but didn't tell me? ;-) ) the
adapter and drive are in the machine and working fine. Unfortunately
the performance isn't what I might have hoped for. Both hdparm &
bonnie++ are reporting numbers in the 200MB/S range rather then the
400-500MB/S range that I might have hoped for. The machine is PCIx-2
based according to its specs.

I'm currently just using a single large partition & ext3. I didn't
do anything special in fdisk so the partition might not be aligned as
best it could be. I don't know.

I'm wondering what sort of experience folks have had trying to get
performance numbers anywhere close to these specs?

Thanks,
Mark

http://www.amazon.com/gp/product/B002VEWBGO/ref=oh_details_o01_s00_i00
http://www.amazon.com/gp/product/B007R1FH3K/ref=oh_details_o01_s00_i02
 
Old 08-22-2012, 10:58 PM
Paul Hartman
 
Default SSD performance tweaking

On Wed, Aug 22, 2012 at 4:46 PM, Mark Knecht <markknecht@gmail.com> wrote:
> Hi,
> Yesterday I got a new, but rather low-end, PCIe-2 SATA-3 6Gb/S
> adapter card and a reportedly high performance 128GB SSD drive. (Links
> below) Other than my swap getting messed up because it didn't use
> labels (who knew about swaplabel but didn't tell me? ;-) ) the

"mkswap -L name /dev/sdX"

> adapter and drive are in the machine and working fine. Unfortunately
> the performance isn't what I might have hoped for. Both hdparm &
> bonnie++ are reporting numbers in the 200MB/S range rather then the
> 400-500MB/S range that I might have hoped for. The machine is PCIx-2
> based according to its specs.
>
> I'm currently just using a single large partition & ext3. I didn't
> do anything special in fdisk so the partition might not be aligned as
> best it could be. I don't know.
>
> I'm wondering what sort of experience folks have had trying to get
> performance numbers anywhere close to these specs?

Because it is a PCIe x1 slot card, that is the bottleneck. Based on
all I have read, your speeds are normal and you should consider it to
be the fastest speeds you'll see. If you had bought two SSDs and used
them in a RAID configuration, the speed would actually get worse.

I ran into the same thing a while back, my motherboard actually has
SATA3 on-board, but it is not the primary controller (that one is
SATA2) and it's basically a permanently-installed PCIe controller as
far as speeds are concerned. Because of added latency, the on-board
primary SATA2 is actually faster than the SATA3 when multiple drives
are attached... but it's still faster than a HDD anyway.

I think the only way we'lll see 500MB/sec on that SSD is to buy a
motherboard which has a SATA3 controller as its primary on-board drive
controller and plug it in to that.

Look on the bright side, someday when we upgrade our motherboards,
it'll be like we got a free SSD upgrade for our troubles.
 
Old 08-22-2012, 11:24 PM
Dale
 
Default SSD performance tweaking

Paul Hartman wrote:
> On Wed, Aug 22, 2012 at 4:46 PM, Mark Knecht <markknecht@gmail.com> wrote:
>> Hi,
>> Yesterday I got a new, but rather low-end, PCIe-2 SATA-3 6Gb/S
>> adapter card and a reportedly high performance 128GB SSD drive. (Links
>> below) Other than my swap getting messed up because it didn't use
>> labels (who knew about swaplabel but didn't tell me? ;-) ) the
> "mkswap -L name /dev/sdX"
>
>> adapter and drive are in the machine and working fine. Unfortunately
>> the performance isn't what I might have hoped for. Both hdparm &
>> bonnie++ are reporting numbers in the 200MB/S range rather then the
>> 400-500MB/S range that I might have hoped for. The machine is PCIx-2
>> based according to its specs.
>>
>> I'm currently just using a single large partition & ext3. I didn't
>> do anything special in fdisk so the partition might not be aligned as
>> best it could be. I don't know.
>>
>> I'm wondering what sort of experience folks have had trying to get
>> performance numbers anywhere close to these specs?
> Because it is a PCIe x1 slot card, that is the bottleneck. Based on
> all I have read, your speeds are normal and you should consider it to
> be the fastest speeds you'll see. If you had bought two SSDs and used
> them in a RAID configuration, the speed would actually get worse.
>
> I ran into the same thing a while back, my motherboard actually has
> SATA3 on-board, but it is not the primary controller (that one is
> SATA2) and it's basically a permanently-installed PCIe controller as
> far as speeds are concerned. Because of added latency, the on-board
> primary SATA2 is actually faster than the SATA3 when multiple drives
> are attached... but it's still faster than a HDD anyway.
>
> I think the only way we'lll see 500MB/sec on that SSD is to buy a
> motherboard which has a SATA3 controller as its primary on-board drive
> controller and plug it in to that.
>
> Look on the bright side, someday when we upgrade our motherboards,
> it'll be like we got a free SSD upgrade for our troubles.
>
>

I was thinking the same thing when I read the OP's post. I have a older
IDE based machine, about 10 years old, and bought a SATA drive and
card. The performance was less than claimed but it was because the bus
speed was the bottle neck. When I built my new rig, which is SATA
based, the drive was quite a bit faster and I get the speeds I should get.

The only reason I bought that drive and the card was because I knew I
was going to be upgrading and would have SATA on the mobo. OP, when you
get a mobo with SATA built in, you should get better, most likely much
better, performance.

Why is it that all puters seem to have a bottle and a neck in them? lol

Dale

:-) :-)

--
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!
 
Old 08-23-2012, 04:05 AM
Mark Knecht
 
Default SSD performance tweaking

From Kindle so short...

Paul. Thanks. I'll double check tomorrow but the specs online said the
slots were pci express 2.0. The card is a one lane card but the box
says it can do 533M/S but boxes do lie sometimes.

I'll keep investigating and post back any new info.

Thanks,
Mark
 
Old 08-23-2012, 08:14 AM
Volker Armin Hemmann
 
Default SSD performance tweaking

Am Mittwoch, 22. August 2012, 14:46:40 schrieb Mark Knecht:
> Hi,
> Yesterday I got a new, but rather low-end, PCIe-2 SATA-3 6Gb/S
> adapter card and a reportedly high performance 128GB SSD drive. (Links
> below) Other than my swap getting messed up because it didn't use
> labels (who knew about swaplabel but didn't tell me? ;-) ) the
> adapter and drive are in the machine and working fine. Unfortunately
> the performance isn't what I might have hoped for. Both hdparm &
> bonnie++ are reporting numbers in the 200MB/S range rather then the
> 400-500MB/S range that I might have hoped for. The machine is PCIx-2
> based according to its specs.

certainly not. PCIX is something you don't have. PCIe2 - yes
>
> I'm currently just using a single large partition & ext3. I didn't
> do anything special in fdisk so the partition might not be aligned as
> best it could be. I don't know.

that alone can more than half your performance.
Btw, why ext3? 4 and trim is your friend with a ssd.

Your performance is fine. It is a single slot adapter, so the theoretical max
is 300mb/s. Now substract some for overhead and some for misalignment and
200mb/s aren't bad at all.

--
#163933
 
Old 08-23-2012, 10:15 AM
Alex Schuster
 
Default SSD performance tweaking

Mark Knecht writes:


I'm currently just using a single large partition & ext3. I didn't
do anything special in fdisk so the partition might not be aligned as
best it could be. I don't know.


See if the partition's starting block is 63 as it used to be in the
past. In this case the alignment is wrong, as SSDs have 4K (or even 8K)
sectors consisting of 8 (or 16) 512 byte blocks. The starting block
should be divisible by 8 (or 16) because of the large sector size, if
not, a file system sector spans over two drive sectors, and both heed to
be accessed when reading a file system sector.


The size of an erasable block of SSDs is even larger, usually 512K, it
would be best to align to that, too. A partition offset of 512K or 1M
would avoid this.


Wonko
 
Old 08-23-2012, 12:55 PM
"J. Roeleveld"
 
Default SSD performance tweaking

Mark,

On Thu, August 23, 2012 6:05 am, Mark Knecht wrote:
> From Kindle so short...
>
> Paul. Thanks. I'll double check tomorrow but the specs online said the
> slots were pci express 2.0. The card is a one lane card but the box
> says it can do 533M/S but boxes do lie sometimes.

The "2.0" part is the version. Not the speed.
For PCI-e it's usually denoted as 1x, 4x, 8x and 16x.
The numbers specify the amount of PCI-express lanes used for the port.

More lanes = more bandwidth.
As others have already pointed out, it's a single-lane card. Which means
you can only get the max for a single PCI-express lane.

On a side-note, does anyone know of a way to merge multiple PCI-expres 1x
ports together without having to completely rewire the mainboard and
"patch" the BIOS?
My skillset, unfortunately, doesn't include that...


--
Joost
 
Old 08-23-2012, 03:55 PM
Mark Knecht
 
Default SSD performance tweaking

On Wed, Aug 22, 2012 at 3:58 PM, Paul Hartman
<paul.hartman+gentoo@gmail.com> wrote:
<SNIP>
>
> I think the only way we'lll see 500MB/sec on that SSD is to buy a
> motherboard which has a SATA3 controller as its primary on-board drive
> controller and plug it in to that.
>
> Look on the bright side, someday when we upgrade our motherboards,
> it'll be like we got a free SSD upgrade for our troubles.
>

Support for your POV Paul:

http://techgage.com/article/battle_of_the_sata_30_controllers/

My controller is also a Marvell and the machine is X58-based so
results are likely to be similar.

I'm likely fighting a losing battle here, but I'll keep fighting for
awhile longer...

Cheers,
Mark
 
Old 08-23-2012, 06:57 PM
Mark Knecht
 
Default SSD performance tweaking

On Thu, Aug 23, 2012 at 8:55 AM, Mark Knecht <markknecht@gmail.com> wrote:
> On Wed, Aug 22, 2012 at 3:58 PM, Paul Hartman
> <paul.hartman+gentoo@gmail.com> wrote:
> <SNIP>
>>
>> I think the only way we'lll see 500MB/sec on that SSD is to buy a
>> motherboard which has a SATA3 controller as its primary on-board drive
>> controller and plug it in to that.
>>
>> Look on the bright side, someday when we upgrade our motherboards,
>> it'll be like we got a free SSD upgrade for our troubles.
>>
>
> Support for your POV Paul:
>
> http://techgage.com/article/battle_of_the_sata_30_controllers/
>
> My controller is also a Marvell and the machine is X58-based so
> results are likely to be similar.
>
> I'm likely fighting a losing battle here, but I'll keep fighting for
> awhile longer...
>
> Cheers,
> Mark

One additional thought:

This limitation is likely just a byproduct of using a 1 lane
controller. If one was willing to spend a (fairly large) bit more one
could get a 16 lane SATA3 controller and would likely do much better
in terms of throughput...
 
Old 08-23-2012, 07:22 PM
Neil Bothwick
 
Default SSD performance tweaking

On Thu, 23 Aug 2012 11:57:25 -0700, Mark Knecht wrote:

> This limitation is likely just a byproduct of using a 1 lane
> controller. If one was willing to spend a (fairly large) bit more one
> could get a 16 lane SATA3 controller and would likely do much better
> in terms of throughput...

If you want real performance from SSD, you ditch SATA altogether and use
a drive on a dedicated card. Of course, you're talking real money now.


--
Neil Bothwick

OPERATOR ERROR: Nyah, Nyah, Nyah, Nyah, Nyah!
 

Thread Tools




All times are GMT. The time now is 07:27 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org