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#323513 - 19/06/2009 18:37 Re: SSDs [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Originally Posted By: mlord
Note that the 120GB Vertex drive here is in my main development / daily-use machine. According to the SMART data it has now averaged 33 erase cycles across all of the flash.

Only 99967 cycles left! smile

(that's around 50-years at the current rate of use).

Mmm.. math error there.

The count is now an average of 34 erase cycles across all of the flash, after 76 power-on hours over 10 weeks or so. It's a notebook, and it's only powered on when I'm actively using it.

So, let's try that math again now:

10 weeks / 34 cycles = .29 weeks/cycle.
The flash chips are rated for 10000 cycles minimum,
so that's 10000 * .29 = 2900 weeks of use before it dies.

Which still works out to more than 50 years.

Another way is to do it by hours of use:
76 hours / 34 cycles = 2.2 hours/cycle,
so that's 10000 * 2.2 = 22000 hours of use before it dies.

Figure worst case of perhaps 40 hours of use per week,
that's 40 * 52weeks = 2080 hours per year.
At that rate, the drive would wear out
in 22000 / 2080 = 10.5 years of use.

I think I might have *one* other drive in the house that's survived 10 years, but it hasn't had nearly that amount of use.

Cheers

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#323514 - 19/06/2009 19:00 Re: SSDs [Re: mlord]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: mlord
Note that the 120GB Vertex drive here is in my main development / daily-use machine. According to the SMART data it has now averaged 33 erase cycles across all of the flash.

Which SMART attribute tells you the number of cycles? Some of the ones being reported by mine are pretty weird like 0xCE - Flying Height.

I tried looking for information on SMART attributes in the OCZ forum and all I could find was a handful of threads where a moderator keeps saying that SMART doesn't work and won't ever work for SSDs. The numbers being returned by the SMART commands are nothing you should be looking at. Go away. Thread closed.

Helpful...

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#323518 - 19/06/2009 23:13 Re: SSDs [Re: tman]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
These two smart data fields have been documented by OCZ:

http://www.ocztechnologyforum.com/forum/showthread.php?t=57898

Field 208 (0xD0) is "average block erase count".
Not sure what the scaling factor is, though, since it's
only an 8-bit field and the cells are good for 10000 cycles minimum.

208 Spin_Buzz 0x0000 031 000 000 Old_age Offline In_the_past 0

Field 209 (0xD1) is "Remaining drive life in %% by erase count".
So probably (field_208 / 10000) * 100%, except we know field_208 hasn't enough bits.

209 Offline_Seek_Performnce 0x0000 100 000 000 Old_age Offline In_the_past 0

Fields 001 (read error rate) and 009 (power on hours) are also valid.

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#323520 - 19/06/2009 23:29 Re: SSDs [Re: mlord]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Ahh. Thanks for the link. It would be helpful if Indilinx actually published more details on the various attributes.

0xD0 is 13 and 0xD1 is 100 for mine. Bit strange that its done 13 erases though since I've only installed Windows on it the other day. Reading the forum also shows some odd values. Its at 100% anyway for 0xD1 so I guess its all good still.

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#323833 - 29/06/2009 13:43 Re: SSDs [Re: drakino]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
ooo, 320GB Intel SSDs. Hopefully the rumor is true of better capacities and noticeably discounted prices. 320gb would be enough to let me swap out the Velociraptor and gain a little bit of space.

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#323834 - 29/06/2009 15:42 Re: SSDs [Re: drakino]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: drakino
ooo, 320GB Intel SSDs. Hopefully the rumor is true of better capacities and noticeably discounted prices. 320gb would be enough to let me swap out the Velociraptor and gain a little bit of space.

That 320GB won't be cheap though! The prices of the 250GB should be more reasonable however.

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#323835 - 29/06/2009 18:50 Re: SSDs [Re: tman]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
In the traditions of companies aiming for overclockers, OCZ are releasing a special matched chip version of the Vertex which is a whole 10% faster.

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#323850 - 30/06/2009 01:11 Re: SSDs [Re: tman]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
Quote:
OCZ says...
*Consumers may see a discrepancy between reported capacity and actual capacity; the storage industry standard is to display capacity in decimal. However, the operating system usually calculates capacity in binary format, causing traditional HDD and SSD to show a lower capacity in Windows. In the case of SSDs, some of the capacity is reserved for formatting and redundancy for wear leveling. These reserved areas on an SSD may occupy up to 5% of the drive’s storage capacity. On the Vertex EX Series the naming convention reflects this and the 60 is equivalent to the 64GB and 120 is equivalent to 128GB.


Ok, I read it, but it's not making explicit sense.

Are SSD's sized in real (^2) or fake (decimal) GBs? Before or after formatting?
_________________________
Glenn

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#323851 - 30/06/2009 01:16 Re: SSDs [Re: gbeer]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: gbeer
Are SSD's sized in real (^2) or fake (decimal) GBs? Before or after formatting?

It actually has real powers of 2 GB in there but the flash controller uses some for wear leveling and you also lose a bit from formatting etc... Basically what OCZ sell it at is what usable space there is after formatting.

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#323853 - 30/06/2009 01:35 Re: SSDs [Re: tman]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
Originally Posted By: tman

It actually has real powers of 2 GB in there but the flash controller uses some for wear leveling and you also lose a bit from formatting etc... Basically what OCZ sell it at is what usable space there is after formatting.


So comparing a 60GB SSD and a 60GB HDD, is it apples to apples?

Do SSD makers subscribe to the same ^10 size ratings that HDD makers use?


Edited by gbeer (30/06/2009 01:52)
_________________________
Glenn

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#323854 - 30/06/2009 01:51 Re: SSDs [Re: gbeer]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
The idea is that a "60GB" OCZ Vertex is equivalent to a "64GB" model from any other manufacturer.

And they'll probably stop trying to be honest about it in the future, since so many people seem to have difficulty with the concept. frown

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#323855 - 30/06/2009 02:00 Re: SSDs [Re: mlord]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
It's mostly a point of curiosity, for me. As long as all SSD's are rated the same way.

Though I am of the camp where HDD's should have been rated in GB^2s.

_________________________
Glenn

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#323892 - 01/07/2009 15:53 Re: SSDs [Re: mlord]
Tim
veteran

Registered: 25/04/2000
Posts: 1522
Loc: Arizona
Originally Posted By: mlord
When I said, "Best.. Upgrade.. Ever..", I really meant it. This drive just smokes anything (SSD or mechanical) that I've ever played with before.

Based on your recommendation and the Anandtech article, I got a 120GB Vertex for a new install. So far, I love it. I was worried about space, but that hasn't been a problem yet (still have about 25GB free). It is stupidly fast. I hate having to go back to the old disk setup (RAID0 7200RPM drives with a VelociRaptor data drive - 1.3TB in space) because the speed difference is very noticable. Personally, I think it is worth the size limitations and cost for the performance boost.

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#323897 - 02/07/2009 01:59 Re: SSDs [Re: Tim]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
Are you chaps talking about having purchased the SLC or MLC version of the 120GB Vertex drive.
_________________________
Glenn

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#323906 - 02/07/2009 11:04 Re: SSDs [Re: gbeer]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Originally Posted By: gbeer
Are you chaps talking about having purchased the SLC or MLC version of the 120GB Vertex drive.

Dunno about you guys, but I'm not that wealthy. wink

Definitely the original MLC drive!

Cheers

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#323948 - 05/07/2009 16:40 Re: SSDs [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Originally Posted By: mlord

Ensure that your Windows partition starts at sector 1024, rather than the usual 63 which incurs quite a performance hit.


I assume this is important for Linux partitions too.
Can you give me any pointers how to optimally fdisk an SSD?

Thanks,
Pim

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#323949 - 05/07/2009 17:48 Re: SSDs [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Just put the first partition at a sector offset of 1024, rather than the default of 63. In practice, even an offset of 64 is good enough (any even multiple of 4KBytes).

The default of 63 is horrid, since it means every 4KB write to the disk can potentially require an internal READ/MOVE/MODIFY/WRITE cycle. Really bad for performance, that! smile

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#323954 - 06/07/2009 11:41 Re: SSDs [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
How would I do that with fdisk? It asks me for a start cylinder which usually is a unit of 255*63*512 bytes.

Does it mean changing the number of sectors per track?

Thanks,
Pim

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#323956 - 06/07/2009 15:12 Re: SSDs [Re: pim]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4172
Loc: Cambridge, England
I think you need fdisk's "expert mode" to make partitions on non-cylinder boundaries. (But I don't have Linux in front of me to check exactly how.)

Peter

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#323957 - 06/07/2009 15:24 Re: SSDs [Re: peter]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
The "u" command will switch fdisk to sector units.

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#324029 - 08/07/2009 06:52 Re: SSDs [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Originally Posted By: mlord
In practice, even an offset of 64 is good enough (any even multiple of 4KBytes)


Would changing the number of heads to 128 and the number of sectors per track to 32 do the same trick? Cylinders would then be multiples of 4KB.

Given that OS installers usually pick cylinder boundaries, I could then have the OS installer do the partitioning.

Thanks,
Pim

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#324046 - 08/07/2009 19:26 Re: SSDs [Re: pim]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3995
Loc: Manchester UK
Has anyone come across 3.5 inch SATA/SAS SSD's they could recommend? Got some poweredges I'd like to convert.
_________________________
Cheers,

Andy M

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#324050 - 08/07/2009 21:41 Re: SSDs [Re: andym]
Phoenix42
veteran

Registered: 21/03/2002
Posts: 1424
Loc: MA but Irish born
No. But you could modify a drive carrier with different mounting holes to put the connections in the right place. I've seen this done on a lab system.

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#324051 - 08/07/2009 21:56 Re: SSDs [Re: andym]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Originally Posted By: andym
Has anyone come across 3.5 inch SATA/SAS SSD's they could recommend? Got some poweredges I'd like to convert.

What is your budget? I've used STEC ZEUS-IOPS (stupid superscript name) 3.5" FC SSDs before and they worked well. They do a SATA and a SAS version as well.

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#324056 - 08/07/2009 23:17 Re: SSDs [Re: tman]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
_________________________
Glenn

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#324057 - 09/07/2009 00:33 Re: SSDs [Re: andym]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Originally Posted By: andym
Has anyone come across 3.5 inch SATA/SAS SSD's they could recommend? Got some poweredges I'd like to convert.

They mostly seem to be 2.5" form factor right now. But some companies (eg. OCZ) also market conversion brackets for 3.5" bays, which will work with any 2.5" drive.

Cheers

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#324569 - 24/07/2009 14:45 Re: SSDs [Re: tman]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Just received the OCZ Vertex 32GB drive I ordered.

First thing to do was to see whether it is as fast as advertised.

What I'm seeing is that the read speed greatly depends on the SATA controller. I tested on three different PC's using this command:

dd if=/dev/sdX of=/dev/null bs=1024k count=8192

(I made sure to flush the cache by first dd'ing another drive)

Results:
ICH7, ahci: 78 MB/s
ICH7, ata_piix: 125 MB/s
ICH8, ahci: 78 MB/s
ICH8, ata_piix: 132 MB/s
ICH10, ahci: 78 MB/s
ICH10, ata_piix: 187 MB/s
sil3132, ahci: 72 MB,s
Marvell 88SE6121, pata_marvell: 138 MB/s

Interesting to see is how bad AHCI performs. Wasn't AHCI supposed to be "superior"?

For regular SATA drives, AHCI versus IDE mode does not seem to matter, at least for sequential read speeds, but choosing IDE mode would disable NCQ. Would that slow down regular SATA drives?

Thanks,
Pim

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#324580 - 24/07/2009 18:22 Re: SSDs [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
A simple dd won't saturate the drive, though it might have a decent shot if drive "read-ahead" is enabled.

Things for you to do:

1) upgrade to OCZ firmware 1.3 immediately, if not already on the unit.

2) ensure the drive is set for highest performance:
hdparm -W1 -A1 /dev/sdx

3) stop benchmarking, and just enjoy the speed! wink

As for AHCI, its pluses are (1) it's now a multi-vendor standard, which means new devices that implement it won't need to write drivers from scratch, and (2) it fully supports NCQ (multiple overlapping R/W commands at once to the drive). Point (2) helps servers much more than desktops/notebooks, and benchmarks generally show that the OCZ Vertex doesn't really take much advantage of it.

Cheers

Cheers

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#324605 - 25/07/2009 08:00 Re: SSDs [Re: mlord]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Just for everybody's information:

Intel has released their new "Postville" SSD's. These SSD's use the smaller 34 nanometer chips, compared to the previous models which used 50 nanometer chips. This has made the Intel SSD's even faster and... considerably cheaper as well! The 80 GB model now costs less than the 60 GB OCZ Vertex model does! Or should I say did, because OCZ has already responded by lowering their prices as well.

On this (Dutch) site you can find a table which shows an overview of both the Intel and OCZ SSD's at the moment, with the capacity, price per GB and recommended retail price.

Mark, that OCZ Agility range (also in the table), is that one comparable to the Vertex series?
_________________________
Riocar 80gig S/N : 010101580 red
Riocar 80gig (010102106) - backup

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#324607 - 25/07/2009 11:05 Re: SSDs [Re: BartDG]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Originally Posted By: Archeon
Mark, that OCZ Agility range (also in the table), is that one comparable to the Vertex series?

Yes, the Agility has the same Indilinx Barefoot controller chip, but uses cheaper (usually slower) flash chips than the Vertex.

I also seem to recall that it has only half the channels (bandwidth) to/from the controller, but I cannot find where I thought I once read that. EDIT: Oh, perhaps something in this rather confusing thread.

In practice, The Agility normally performs so close to the Vertex that there's just no point in paying more for a Vertex now. smile Or at at least that's true for a SATA1 interface like the one in my notebook here.

And gotta love the pricing on the Intel G2 SSDs, too. Things are excellent in this space, and still getting even better very quickly!

Cheers


Edited by mlord (25/07/2009 11:40)

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