Bottom Line - You get what you pay for. Without going into a rediculous amount of detail, because I'll let the internet do it for me.
There is a huge difference between an Enterprise SSD like the Optimus or Sandisk Lightning or the Intel 3700 and the Samsung 840 or OCZ Vector. There's a pretty darn good review Tweak Town SSD Review.
That review highlights the differences chief among them SUSTAINED performance. There are also a few other points that I think make all the difference:
Reliability - Enterprise SSD are made to run in a datacenter environment which typically means a higher sustained operating and level. They are built to run all out for extended periods of time at higher temps in more demanding environments.So please consider a couple things when making this decision:
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- The use of your drives: The drives that are housing something very volatile will get beat up a lot more, stuff like caching drives or database tempdb. By the nature if those types of use those will get over written a lot and that may be worth the extra investment for extended life.
- How prepared you are to deal with replacement and such when the time comes. Depending on your architecture and it's built in reliability (fail-over clusters and the like) maybe you can live with it being down for a while as you order replacement parts. Maybe you can afford to have some the shelf just in case. If you choose to put all your eggs in one basket for what ever reason then I usually counsel people to make that basket as bullet proof as possible. In the end you have to do what is right for the business and your situation.
Data Protection - Enterprise SSDs have protections against power loss and the like built in. They will make sure all writes get committed before they go offline.
The Dell controller should support mixed drives - it actually says it supports mixed drives.
If you have support on your server and you purchase your drives from them then your drives will be supported in your contract. This is a business database on a business class server in a Datacenter, so you have 24x7 support right. Oh and one other thing you should always have hot spares in the box ready to replace a failed device the second it fails. After that you just wait for the courier to show up with your replacement drive and pop it in. When asked how much extra that costs you just make a comparison to the amount of downtime you'll experience if you were to actually lose the server for however long it took. That usually justifies the expense.
I know that a lot of the time in IT the cheap quick solution takes a backseat to the proper solution. I would encourage you to talk to your management and find the money to do it right the first time, because when it comes to storage, the sacrificially lamb can oft times be the business itself.
Best Answer
As far as "support" goes, you'll be hard pressed to find this spelled out in the documentation. Most 10th-generation and newer Dell servers have good documentation available with a list of all of the supported drive models, but I've not seen this for the 2950. I can tell you from personal experience that the 2950 never introduced SSD support of any kind. With that being said, it may still work since communication is through a SATA interface. You run the exact same risk as with using any other non-Dell-certified drives, in that there may be problems with a specific model or drive FW that never gets addressed if it's non-certified (hardware and firmware validation testing are only carried out w/ Dell-branded drives). In the end, unless you can find an instance of someone having documented a test with the exact hardware combination as you (same server, controller, and SSD model), you're just not going to be able to know without testing it out.
In regards to comments on controller performance... The PERC controller itself can often become a bottleneck when using SSDs, especially when you get into older (ancient) cards like the PERC 5/i, and even newer cards if your I/O footprint is write heavy & random, e.g. a database of some kind. Go with the newest card your system is compatible with (PERC 6/i) if it's an option for you.
Another note on performance - LSI controllers (rebranded as PERC w/ Dell) don't currently support SSD TRIM like typical (newer) desktop integrated RAID controllers do. Long story short, that means that you're going to see very poor write performance after a bit of use unless you use a model w/ built-in garbage collection (e.g. SSDs with Sandforce controllers, like those made by Intel).