New SSD not reaching the advertised speeds


Aug 21, 2011

so i recently build a pc, like 1 week ago and i bought a OCZ Vertex 3 120gb as my main boot and apps drive, like this is my first SSD, at first (and still) i thought it was very fast, then i thought of testing it to see if it reaches the advertised speeds...

and this is the result:


This is a lot slower than the supposed 550/500 mb/s speed....... whats wrong???

and what does "pciied- BAD" means????


I have connected it with a SATA cable that came with my MOBO, it said 3gb and 6gb......

I have connected it to a SATA III connector

i have not changed anything in BIOS, not even entered once... does anyone knows whats the problem??

and till today, i have never had any problems with the SSD (no blue screen, no freezing..)

I disabled sleep

My pc is ON 24 hours

Also... yesterday (i think), i read that it is better to move the temp files and paging files to another hard drive (normal), for the SSD to not degrade quickly because of the constant read/write........... is this true?? should i do it?? or will i have problems moving these files?... and if yes, how do i do this.... ??

thanks for your help

My build:

CPU: i5-2500k, not overclocked (yet)
MOBO: Gigabyte z68x-UD4-B3
Gpu: PNY GTX 570
Ram: Corsair vengeance 2 x 4gb (8gb) 1600mhz
case: haf X
PSU: Cooler Master Silent Pro 850 watts
Boot drive: OCZ Vertex 3 120gb
OS: Windows 7 SP1

i think thats all
One thing you have to be careful about is the way the desciption and spec's are worded and what I mean by that is you will notice that OCZ says ' UP TO " a certian speed. You will most likely not be getting 550 read and 500 write you will be getting something less , and every SSD will get a different speed even though they are the same model and spec's . One thing you can do is in the bios enable AHCI , that should give you an increase. You may have to go on the OCZ forums to see how to do that since you have already loaded your OS. Or you can reformat and reload the OS and before you reload enable AHCI.
Advertised AS-SSD specs for your drive are "up to" 500 MB/s Read and 155 MB/s Write.
If you are looking for the advertised "up to" 550 MB/s Read and 500 MB/s Write you have to benchmark with ATTO software.

Your speeds are slow because your drive is in IDE mode and your drive is also not aligned properly. "pciide" means that your drive is in IDE mode. "Bad" means that your drive is misaligned. If you cloned or imaged from another HDD or SSD to your Vertex 3 it was not done properly. That is why you see "Bad" in Red.

Your SSD need to be in AHCI mode. You need to perform a Windows Registry fix in order to change to AHCI after you’ve already installed Windows.
Follow the steps in this link to edit your Windows Registry file:

After performing the fix reboot into BIOS, change the SATA mode of the port your SSD is connected to to AHCI.

Download Paragon Alignment Tool software to correct your alignment.

If you do not wish to do the Registry fix or use the alignment software the best thing to do is to start over with a clean installation of Windows.

Also make sure your SSD is connected to 1 of the 2 Intel SATA 6Gb/s ports (SATA3_0 or SATA3_1), and not 1 of the 2 Marvell SATA 6Gb/s ports (GSATA3_6 or GSATA3_7). The Intel ports offer better performance.

Something is definitely WRONG. You're only getting about 60% of the proper speed on every test which is very odd.

I couldn't even come up with a good reason.

To do:
1. verify it is a Vertex 3 (It must be; I'm just being thorough)
2. update the firmware
3. contact OCZ if problem persists.


Aug 21, 2011

Sorry for not answering earlier, but i was busy, thanks all for your help!!

i followed and did some of the recommended "tweaks" from the link danraies posted..
-disabled index
-disabled scheduled fragmentation
-disabled system restore

i think i only did this ones, they had many recommendations, but im not sure of doing them all... should i delete the paging file?? will i benefit from this?? they said to do this, but i would better like to move it to another hard drive

another one, was to disable "turn off hard drives after x min".... i have also 2 2tb hard drives.... so, should i do this?? my drives will never turn off, and i dont know if this will be good as my pc is ON 24 hours.........

i did also what dereck suggested, i edited the registry and changed IDE to ACHI... My BIOS seems to change ALL sata to ACHI (i cannot choose which ones...), so, do this affect in any way my 2 tb hard drives and dvd drives????? will they be slower??

right now im copying 550gb from an external hard drive (toshiba 640gb, i think 5400rpm) to my just arrived Samsung Ecogreen F4 2TB (5400rpm)..... speed is: 33 mb/s =S... is ACHI affecting in any way? or is this just normal??

and i tried again AS SSD Benchmark and got this results:


I think it cant increase more than this (right?)...... my writing speed is still far from the "supposed" 500 mb/s...

thanks a lot everyone!!


Aug 5, 2011
You shouldn't have to disable scheduled defragmentation. Windows 7 will detect your SSD and the SSD won;t be on the list of drives available for scheduled defragmentation. In fact, you really should not have to do anything for an SSD.

I'm not sure what windows is supposed to do, but I did have to disable defragmentation in Windows 7 and also perform several of the tweaks for my drive. It can't hurt to check.


Feb 20, 2010
Dereck was right about everything else so far.. but why haven't you run the recommended ATTO benchmark to see what the drive does with easily compressible data?

Using a benchmark that uses incompressible data on a drive that utilizes data compression will give you those numbers and all is normal for a Sandforce controlled drive. CDM3 will use similar test data as well and great caution should be taken to not run those types of benchmarks on these drives as they will eventually dirty up and throttle the speeds.


May 23, 2008
all I/O devices, are raw speed, that is how Electronics is rated , how fast at the port actual.
you then have software overhead access that port. (any )
that is the first layer of overhead.
if you want boot to dos and write program using the Assembler. and see how fast you car read that port in a tight loop.
this way , you can come near true I/o speed and not reach it. see?
I'm retired, but im the guy who ran the hardware testers (ATE) that measured those speeds.

think of it like , a water pipe
remove the faucet and see how much flow you get (raw)
then attach a valve and hose and 10 feet of hose. now it's less.

the hose,valve and added parts are the equivalent of "software overhead"
and keep in mind that SSD dont just plug in to your over clocked MOBO, it fits other electronic systems too. (vast possibles there)

so the raw , speed is the true speed, if you don't like that speed you get then
run linux or run other more efficient OS.

What you need to compare , is your platform to othesr that are the same. then you will have reality.

I hope this clears up this myth about product data sheets, (read the fine print, its all there , i promise)