If you want to give your notebook or desktop PC a major speed boost, Crucial's m4 256GB solid state drive is a must-have. It's one of the fastest drive's on the market and it'll not only speed up boot times if used as a system drive, it'll make your applications launch almost instantly. The only drawback of this drive is its high price, but if you absolutely need the speed and you can afford it, it's well worth it.

Physically, the Crucial m4 is 8.5mm thick and it will fit into any laptop that has a standard 2.5in drive bay. The drive itself resides in a sturdy case that protects the memory chips and it weighs about half as much as a typical 2.5in mechanical drive. There are mounting holes along the sides and on the underside of the drive. It gets only lukewarm during regular operation and once it reaches that level it doesn't get any warmer, so it will make your laptop run a little bit cooler as a result.

It has a standard Serial ATA interface and it supports up to 6Gbps operation. We tested it in an HP Pavilion dv7 notebook, which is a high end model with two hard drive bays and is therefore a prime candidate for an SSD upgrade. As a system drive, the Crucial m4 outperformed the standard drive that comes with the dv7 (a 5400rpm Toshiba) by miles. CrystalDiskMark recorded sequential read and write speeds of 382.9MBps and 253.1MBps, respectively. That's not far off the 415MBps read time that Crucial specifies in its product description. The 5400rpm drive recorded only an 84.78MBps read speed and an 84.56MBps write speed.

As a reference, we also compared the Crucial m4 to the older and smaller Crucial RealSSD C300 64GB SSD. That drive recorded a sequential read speed of 353MBps in CrystalDiskMark, which is not far off the m4's 382MBps speed, but the m4's write speed of 253MBps is way ahead of the C300's 74MBps. Another drive we compared against was Intel's 80GB SSD, which recorded a read speed of 210MBps and a write speed of 84MBps. You can tell by these results that the Crucial m4 is a high end drive that's not to be messed with.

In the ATTO Disk benchmark, we saw a nice and steady increase in read speeds from small files to large files. Like most drives, the Crucial m4 will be slowest when dealing with lots of small files, but it will still be noticeably faster than a regular hard drive and many other SSDs. In fact, it produced excellent write speeds of 94MBps for 2KB files, 192MBps for 4KB files and 267MBps for 16KB files. Its read times of these files were slower than the write times, but the read times really picked up when dealing with large files, maxing out at 454MBps for 8MB files.

When the Crucial m4 SSD is not given the task of running the operating system and is just left as a secondary data drive, it's even faster. However, you'll get the most benefit from this drive when it is used as a system drive because applications will launch almost instantly.

As well as all the performance benefits while running the system, the Crucial m4 will significantly improve boot times. We clocked it 18sec on the Pavilion dv7, which is 21sec faster than what that notebook did with its standard mechanical drive (39sec). We also tested the battery life of the Pavilion dv7 with its standard 5400rpm drive configuration and with the Crucial m4 SSD installed as the system drive, the Crucial m4 gave the notebook an extra 10min of battery life.


Overall, it's not hard to love this drive, even if it is quite a hefty investment. Its 238GB formatted capacity gives it a cost per gigabyte between £1.10 and £1.80 depending on where you buy it. If you've got a high end laptop or desktop and speed is of the utmost importance to you, then we think you should definitely consider this drive. It will provide a speed boost that will be noticeable from the moment you switch on your computer.