With the older firmware 0002 in our first m4 SSD review, we discover that in IDE mode and after a few reading and writing cycles in spite of correct C400 SSD alignment only slow and fluctuating reading rates were reached. The performance was at that time some times so slow, that we assumed a defective SSD. Directly after the TRIM the performance went back to the default fast values. According to Crucial support this was attributed to the new NAND memory, which has a higher density of 8K with the 256GB m4 SSD and not the 4K block size as with the smaller SSDs or the C300 RealSSD. Today, with the new firmware versions 0309 and 000F we did not notice this phenomen again, so it is already at this point recommended to update the SSD to one of these current firmware downloads.

In IDE mode with the FW 0309 AS SSD measured approx. 450 MB/s, the maximum transfer rate of the Serial ATA 2.0 interface was exceeded, so that a SATA3 interface is really the best choice for this SSD. The previously firmware 0002 contrary to this result achieved only 275 MB/s. The write performance in IDE mode was approximately 278,57 MB/s, which is much faster than approximately 241 MB/s of the older firmware version 0002. The overall score reached in IDE mode very good 325 points. In comparison to this result, the FW0002 reached 291 points, an OCZ Agility 120GB SATA2 SSD reached 138 points and a 256GB C300 SSD reached 290 points.

Here is a Snipping screenshot of the AS SSD benchmark results (Firmware 0309 SATA3 IDE):

In AHCI mode also another result beneath the read performance was much higher than in the IDE mode and that is the important value “4K-64Thrd”. 4K means that small 4K blocks are read and/or written and with the 4K 64Thrd this is distributed on 64 Threads at the same time. Thus the benchmark program simulate for example a typical program start. Since the weighting of this value is very high in the AS-SSD benchmark tool,the total score in AHCI mode is with 576 points (530 points with FW0002) much higher than the same benchmark in IDE mode. In AHCI mode the Crucial m4 256GB reached even 495 MB/s read- and 252 MB/s write performance (410MB/s read- and 266MB/s write performance with FW0002), which currently beats the highest score in our reviews. The most current firmware 000F published yesterday achieved 484 MB/s read- and 276 MB/s write performance.

Here is a Snipping screenshot of the ATTO Disk benchmark values (Firmware 0309 SATA3):

Compared to this result, the read performance in AHCI mode is significantly increased starting with a transfer size of 32k. Here we see can see a very good comparison of the conventional native IDE mode and the modern AHCI mode, which offers beside the higher performance also advantages like e.g. the support of NCQ (Native Command Queuing) or Hot-Plug. With ATTO above all clear improvements of the firmware 0001 compared to the firmware 0309 could be recognized, but the firmware 000F is with ATTO somewhat slower.

Here is a Snipping screenshot of the ATTO Disk benchmark values (Firmware 0001 SATA3 AHCI):

Here is a Snipping screenshot of the ATTO Disk benchmark values (Firmware 0309 SATA3 AHCI):

Here is a Snipping screenshot of the ATTO Disk benchmark values (Firmware 000F SATA3 AHCI):

The ATTO disk benchmark values are compared with a small transfer size of 32KB and a large transfer size of 8192KB. The bar chart already shows a first comparison to the Hitachi Deskstar 7K1000.C 1TB hard disk drive, the OCZ Agility 120GB SSD, the Crucial 256GB C300 RealSSD and a lot of other SSDs, where this Crucial m4 barely didn’t reach the top 8192K and 32K result.

Here is a comparison of the ATTO disk benchmark values, which are getting updated with soon coming drives:

Here is a Snipping screenshot of the CrystalDiskMark values (Firmware 0309 SATA3):

As seen in the previous 4K-64Threads results, the read and write 4K QD32 and the sequential read result is much higher when operating in AHCI mode. With CDM clear improvements of the firmware 0001 to the firmware 0309 could be determined, additionally the firmware 000F improved again the read value.

Here is a Snipping screenshot of the CrystalDiskMark values (Firmware 0001 SATA3 AHCI):

Here is a Snipping screenshot of the CrystalDiskMark values (Firmware 0309 SATA3 AHCI):

Here is a Snipping screenshot of the CrystalDiskMark values (Firmware 000F SATA3 AHCI):

The following diagram shows the CrystalDiskMark results once again compared with other SSDs and platter drives, which are extended step by step. In the CrystalDiskMark comparison one can see significant differences between the to-date tested of the Solid State Drives and Hard Disk Drives, where the tested Crucial m4 256GB SSD or Micron RealSSD C400 256GB SSD has the fastest sequential read performance in AHCI mode with the firmware 000F.

Here is a comparison of the CrystalDiskMark values, which are getting updated with soon coming drives:

Here is a Snipping screenshot of the SiSoftware Sandra benchmark values (SATA3 IDE):

In AHCI mode SiSoftware Sandra measured the to-date fastest result of 507.81 MB/s at the read performance with firmware 0309. The firmware 000F reached 498.89 MB/s and the oldest firmware 0001 achieved the slowest performance of 470.20 MB/s.

Here is a Snipping screenshot of the SiSoftware Sandra benchmark values (Firmware 0001 SATA3 AHCI):

Here is a Snipping screenshot of the SiSoftware Sandra benchmark values (Firmware 0309 SATA3 AHCI):

Here is a Snipping screenshot of the SiSoftware Sandra benchmark values (Firmware 000F SATA3 AHCI):

Here is a comparison of the SiSoftware Sandra benchmark values, which are getting updated with soon coming drives: