G.SKILL FM-25S2S-64GB JMicron Review

G.SKILL FM-25S2S-64GBWhenever a new technology comes along I always tend to be one of the early adopters, and after waiting for a while I ended up biting the bullet and I purchased an SSD hard drive. At the time the G.SKILL FM-25S2S-64GB offered the best price for performance running $160 CDN for the 64gb MLC SSD disk drive. As soon as I installed Windows Vista x64 on my G.SKILL FM-25S2S-64GB I noticed a considerable increase in both boot times, as well as application load times (let’s be honest a 64Gb HD these days is only really big enough for Windows plus a few applications).

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G.SKILL FM-25S2S-64GB Specifications:

  • JMicron JMB322 SATA controller w/ 16Kb cache
  • Available in 32GB, 64GB and 128GB capacities
  • Interface: SATA 1/2
  • Dimensions: 99.88 x 69.63x 9.30 mm
  • Weight: 90g
  • Sequential Read: up to 155MB/s
  • Sequential Write: up to 90MB/s
  • Shock Resistant: 1500G/0.5ms
  • Vibration Resistant: 20G/10~2000Hz with 3 Axis
  • Operating Voltage: DC 5V
  • Power Consumption: 280mA~330mA
  • Operating Temperature: -40°~85°
  • Storage Temperature: -55°~125°
  • MTBF: >1,500,000 Hours
  • Data Retention: > 5 years at 25°
  • Data Reliability: Built-in BCH 15-bit ECC
  • O/S Support: Windows 2000/XP/Vista Linux, and Mac OSX
  • Certification: FCC/CE/RoHS
  • 2 Year Warranty

Now on paper, those specifications don’t look too bad, however, specifications can be deceiving. The problem with the G.SKILL FM-25S2S-64GB which became evident as soon as I started reviewing this drive is the fact that the JMicron JMB322 controller only has a 16Kb cache, which can get saturated extremely easy depending on how many reads and write operations you are currently doing (it starts to queue read and write requests once the cache is saturated causing your computer to stutter). In fact, if you look at the HDTach screenshot below you will see that the throughput constantly ranges from 110MB/s to 145MB/s, instead of having a sustained data rate which would be expected of a solid-state flash memory-based drive.

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G.SKILL FM-25S2S-64GB Benchmarks

HDTach Benchmark

The 16Kb cache really hampers the performance of the G.SKILL FM-25S2S-64GB, the sustained read speed was all over the place (this isn’t normal at all). Also, keep in mind this benchmark is on an unused drive so this is ideal performance as soon as you start to queue up a fair number of disk reads and writes (say your OS drive that also acts as a temp folder when downloading a multi-part download while running some intensive applications or a game this will cause your system to briefly shutter)

Atto Disk Benchmark

Atto produced some very interesting and inconsistent results on the G.SKILL FM-25S2S-64GB, I ran the benchmark several times and got different results every time (note the inconsistent speeds on the HDTach benchmark).


Quite frankly I could put the G.SKILL FM-25S2S-64GB through dozens of additional benchmarks in this review, but there really is no reason given the issues with the JMicron controller. Although this drive is fast with an average read speed of 132.6MB/s sustained for sequential data, the stutter caused by the JMicron chip is very evident in Windows after you get a lot of programs open making it unsuitable for enthusiasts. However, if you’re looking for a low power drive and you only use your computer for email and Microsoft Word then the G.SKILL FM-25S2S-64GB will work just fine.

If you are looking for better quality and faster solid-state drive I would suggest looking at a solid-state disk with an Indilinx controller as they have 256kb of cache which is the same amount of Intel’s high-end X25 drives. G.SKILL now has a Falcon series of SSD on the market with the Indilinx controller, however, I haven’t had the opportunity to put one (or two in striped raid) to the tests.

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5 based on 2 votes
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Solid State Disk 64 Gb 2.5" SATA II
USD $152
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