None of this post should be taken as fact and should challenged as much as possible if incorrect.
This post is only referring to MLC SSDs.
The two factors that make having an SSD a good experience are 1. the super low access times and 2. the super fast random write speed.
They key to buying an SSD is the controller. There are four major SSD controllers brands: JMicron, Samsung, Indilix and Intel.
In a nutshell
JMicron: generally avoid
Samsung: Reliable yet not as fast as the competition (Intel and Indilix), but not as expensive either.
Indilix: Best price/performance, good random write speed with great max sequential write speed.
Intel: Most expensive, hands down the best random write speed but at the expense of a much lower sequential write speed.
NOTE: SSD performance can and will degrade over time. There are only 3 possible ways to restore performance to a fresh state:
1. Secure Erase the drive, which involves wiping all of the data (works with all drives)
2. Use manual "wiper" or "garbage collecting" (GC) tools (only works with certain drives)
3. Rely on TRIM, an automatic background command available in W7 and Linux (only works with drives that support it via firmware)
A. JMicron
1. JMicron JMF602: This is the controller that saw widespread use in the first round of "affordable" SSDs. Unfortunately, due to a hardware defect, the controller caused stuttering during every day use. From a 09/2008 article:
When you cause the JM602’s internal buffer to overflow, your system runs in bullet-time. Applications take much longer to launch and close, windows take longer to appear, and there are distinct pauses in anything you want to do that involves the disk. Want to send an IM? Well, that writes to an IM log - you can expect a pause before you can send your IM. Loading webpages is the worst, reading from and writing to the cache wreaks havoc on these cacheless MLC drives. Just for kicks I tried loading AnandTech while I was extracting a 5GB file on the SuperTalent 60GB MLC, it took over 10 seconds for the website to load. Once the JM602 was free to fulfill the read request, the website just popped up - but until then it was like my DNS was failing. It’s a lot like what happens to your notebook if you try and do too much, the disk quickly becomes a bottleneck.
Thankfully, as we've already seen, this problem is only limited to JMF602 based MLC drives
http://www.anandtech.com/cpuchipsets/Intel/showdoc.aspx?i=3403&p=10
However, Kingston has apparently been able to tweak the firmware for the controller to create a SSD line, the Kingston SSDNow V-Series, which
reportedly doesn't suffer from stuttering and provides an overall good, budget SSD experience. Other than the V-Series drives, all SSDs with the JMF602 controller should be avoided.
AFAIK, no GC or TRIM available.
Drives using JMF602: OCZ Core, Kingston V-Series
2. Dual JMicron JMF602: In an effort to get over the stuttering issue, manufacturers combined two JMF602 controllers in a RAID0-like configuration. This dual-controller was used in the G.Skill Titan and OCZ Apex SSDs. Unfortunately the problem was not resolved completely. Applications such as Firefox made the drive stutter. All dual JMicron SSDs should be avoided.
Drives using dual JMF602: OCZ Apex, G.Skill Titan
SSDs with Samsung controllers have been reliable from the get-go, but aren't as fast as Indilix or Intel controllers. There are two generations of them with the second generation having higher max speeds. Unfortunately, due to the
relatively poor random write speed, I don't recommend these drives.
From what I understand, Samsung has plans to release a firmware update with TRIM support.
Drives using Samsung: OCZ Summit, Corsair P-series
The Indilix controller-based SSDs provide the most bang for the buck, with impressive speeds in every category. Variations in performance amongst Indilix drives, such as the performance OCZ Vertex vs the budget OCZ Agility, come from
using different flash chips. All Indilix drives are recommended as they have good random write speeds, albeit not as good as Intel drives.
Both GC and TRIM are available for Indilix based drives.
Drives using Indilix: OCZ Vertex, OCZ Agility, Patriot Torqx, G.Skill Falcon, Super Talent UltraDrive GX
The Intel controller is the performance king when it comes to random write speed, a key to the SSD experience. However, this is achieved at the expense of a much lower sequential write speed. This performance hit is only noticable when moving around large files, only in those situations do Intel drives lose against Indilix and Samsung drives. Intel has two generations of controllers, the G1 and G2. The G2 has better random write speeds and TRIM support, with no plans at this time to provide TRIM support for G1. For this reason I recommend the G2 drives.
Examples of Intel based drives are: Intel X25-M (G1 and G2), Kingston SSD M Series (only G1 for now, G2 to be released in the future)
What to buy?
The choice really comes down to Intel drives vs Indilix drives. If you move around lots of large files and depend on sequential write speed, the Indilix drives will be better. If you don't, then it becomes debateable which is a better buy. I side with Anand when he says to buy the largest (Intel or Indilix) drive you can afford.
Oh, before I forget, before making your purchase keep in mind that SSDs take a small performance hit when they get filled. Anand says to keep 20% free at all times but I think you'll be fine with say 10%.
The EX on the end of the series denotes that it uses SLC vs MLC on the non-EX series.
