Usure of the X25-M in practiceHere are the results of usure of the X25-M with the new firmware. For a full recap of this phenomenon as well as the results obtained on the Vertex with the same protocol, read this article (pages 2 and 3).
Case 1: Sequential performance – Sequential access only
First of all, here are the sequential read and write speeds (in KB/s) when we carry out only this type of access (one read, one write, one read, one write, one read and a final write, each time on the whole of the SSD, ie 80 GB):
There isn’t a great variation, with read speeds around 211 MB/s and writes at 75 MB/s to 72 MB/s.Case 2: Sequential performance – Random then sequential access
This time we started with a new drive (after HDD Erase) that is then “used” by writing by block of 4 KB randomly for 30 minutes. We carried out the same test as in case 1.
This time there was a significant fall in speeds with reads dropping from 211 MB/s to 147 MB/s on the first run. As you can see however, after carrying out a sequential write the SSD regains its original level of performance on the second run.
In writes, note the big variations on the first run, which correspond to the time when the SSD is reorganising itself. The fall isn’t as significant however; 66 MB/s on the first run and then back to 72 MB/s. With the previous firmware the average write speed sometimes went under 20 MB/s in this type of test!
Case 3: Random performance
Now here is an observation of the change in performance (in I/Os per second) during random writes of 4 KB files. We launch the test on a new SSD, 6 times 5 minutes, then a second time on an SSD whose cells have been previously filled seqentially.
On a new SSD, the X25-M starts with a very good level of performance, more than 6500 I/Os per second and then falls rapidly to 1262 on the 6th run. On a used SSD, it starts at 3022 and falls quickly to 370, but bizarely climbs back to 500 on the last run. In any case this is more than ok for desktop use but you’ll note that with the old firmware random write performace was higher: stability has then been gained at a cost.
For this test, we compared the Intel X25-M with different models:
- OCZ Core V2
- OCZ Apex
- Samsung PM410
- Samsung PS410
- Samsung PB22-J 64 GB
- Samsung PB22-J 256 Go
- Mtron MOBI 3500
The OCZ Core V2 represents what is “best” with the JMicron JMF602/MLC combination, with the Apex a RAID version (two SSDs in one). The Vertex is based on the most recent Indilinx controller. The Samsung SLC and MLC SSDs are in a way the references for the previous generation, and the Mtron MOBI 3500 is an interesting alternative. The Samsung PB22-Js are the new generation of Samsung SSD, here in two capacities as their specs are different. For information we also include the performances of a VelociRaptor, a 3"1/2 Samsung SpinPoint F1 640 GB drive and a 2"1/2 Samsung SpinPoint M5 160 GB.
Different measurements were taken in the course of this comparison. First of all we were interested in the “synthetic” performances of these drives: average access time, sequential speeds and I/O in random and sequential access. Next, were more practical tests, first of all involving an applicative performance index based on PC Mark Vantage and then an evaluation of writing, reading with various groups of files These groups were composed of:
- A collection of large files: 6 files (on average 2.2 GB) totalling 13.2 GB
-Medim sized: 7.96 GB of 10,480 files (each averaging 796 KB)
-Small sized: 2.86 GB of 68,184 files (each averaging 44 KB)
The source or target of reading or writing on the drive was a RAID of three VelociRaptor 150 GB drives that replace the raid of two 150 GB Raptors used in previous tests. This type of measurement is worthwhile because, while the sequential speed gives us an idea of the performance in copying large files, things can be different with smaller ones.
The test machine was based on an X38 chipset mounted on an ASUSTeK P5E motherboard while Serial ATA ports were configured in the bios in AHCI (Advanced Host Controller Interface) so that NCQ could be used, all operating with Vista SP1.
We also added new practical tests so as to provide more useful data for those who want to work out if going for an SSD over there standard hard drive is worthwhile. For this we timed various operations on an other machine based on a P5QC, QX9770, GTX 280 and 2x2 GB of DDR2-1066.