I recently purchased a OCZ Vertex 3 for use in my rig with an EVGA 790i FTW motherboard and I had a hard time finding information on how it would work with this board so I decided to share some of my findings. By no means am I an expert nor am I providing definitive information. I just wanted to help some of those people out there looking for some information on using an SSD with a SATA II or SATA III interface.
 
The first thing I came across is TRIM. I won't go into all of the details but the basic idea is that the TRIM command works with the SSD's garbage collection to reduce the number of writes therefore improving endurance compared to the drive relying on its built in garbage collection alone. I have not posted enough to post links however you can Google TRIM and find out more information in detail.
 
If TRIM is really needed seems up to debate. Modern SSDs theoretically could last for decades with the huge number of writes they are said to have. There are some sources, however, that claim TRIM helps maintain better performance of the drive versus using garbage collection alone and that may be worth it.

So what supports TRIM then? Well the Nvidia controller drivers do not, however the generic Microsoft drivers do. I have read reports of the SSD losing performance when using the Microsoft drivers though. If that is true then you would need to decide if endurance or performance is more important.
 
In my research I also read a lot about AHCI improving performance versus IDE. The only problem is that the Nvidia chipset does not support AHCI. The board does contain a Jmicron PCIe to SATA II controller, however, and the Jmicron controller does support AHCI, which in turn will also provide TRIM support when using Microsoft's AHCI driver. You do not have to put the board into AHCI mode in the BIOS as indicated on many websites out there. The Jmicron controller is already in AHCI mode. You simply have to enable the controller in the BIOS. The SATA ports that connect to the Jmicron controller are the red ones on EVGA 790i boards. They may be another color on boards manufactured by other companies. They will most likely be a different color than the other SATA ports.
 
So why not use the Jmicron controller then? Well the biggest factor is that the Jmicron controller uses a single lane PCIe 1.0 bus so the bandwidth is limited to 2.5 Gb/s which cripples performance compared to a native SATA II port @ 3 Gb/s. But if you want TRIM it may be a viable alternative compared to using the generic Microsoft IDE drivers and may perform just as well if not better.
 
I found that using the Jmicron controller with the generic Microsoft AHCI driver on Windows 7 Ultimate 64 improved my SSD's performance over using the Nvidia drivers, the generic Microsoft IDE drivers, and the updated Jmicron drivers available on their website. I did not test on a clean install and would like to to see what happens. Your mileage may vary. Give it a try and let me know what you find.
 
Lastly, I do want to state that using a SATA III PCIe 2.0 controller addon card would be the best performance solution overall if using a SATA III SSD. This would give you AHCI support and TRIM as well as SATA III (or close to anyway) speeds. The catch is you have to use the card in one of the two PCIe 2.0 x16 slots or in the PCIe 1.0 x16 slot.
 
Keep in mind if you use the PCIe 2.0 slot you will not be able to use SLI. If you use the PCIe 1.0 x16 slot you will need a card that supports PCIe x4 or higher or else you will not see a performance gain. Most reviews I have read with the current crop of PCIe 2.0 x4 cards state that they really only use two lanes instead of four but that still would be 5 Gb/s in the PCIe 1.0 x16 slot. They are much more expensive than PCIe 2.0 x1 cards so they may not be the most economical solution if you plan on building a new rig soon anyway.
 
Hopefully this information helps anyone who is looking to install an SSD on a board with the 790i chipset.
 
*edited to clarify this is for SSDs that use a SATA connection and the clarified explanation of PCIe addon cards

That interesting.. I am using NVIDIA Nforce 15.58 on RAID Stripe and other storage are on NVIDIA nforce serial SATA Controller. Read and write is very good speed and my atto disk benchmark result for c:\ drive :-

  
I can remember I was trying using on Standard dual channel PCI IDE controller driver from Microsoft made my SSD slow down to average 130 to 150 
I have not any problem or crash with NVIDIA Driver 15.58.. for nearly 2 months!!!

This is the results of my corsair P128 sata II.  The image on the left is with the nvidia 15.58 driver.  The image on the right is the MS ide drivers.  Both appear acceptable to me for the sata II drive.  
 
I didn't try to use the Jmicron AHCI controller, I read nothing but bad stuff about that. 

 

Nice one Citabria 
 

Ah thanks for a tips about defreggler. Thanks Sturn A+
 

InputUsername

I just wanted to post to say you're a genius.

 
Thank you for the compliment InputUsername but I'm no genius. I just wanted to look more into the controller because I was intrigued that no one ever used it. I never said it was better. It was just a possible alternative. Unfortunately my earlier benchmarks may have made it look like I was pushing it. I discovered a flaw with my SSD that affected those results. I'll explain a little later as it helps to answer your question.
 

InputUsername

Edit: early results with X25-G2, which are a bit puzzling to be honest. Should they really differ this much and still not be across the board better?

 
To answer InputUsername's question they wouldn't be better across the board and it looks like the culprit is the Jmicron controller's use of a PCIe 1x bus that limits the bandwidth. I mentioned something earlier about this. The PCIe x1 bus limits bandwidth to 2.5Gbps which is slower than what SATA II (3 Gbps) is capable of. This limits the speed and my new benchmarks and InputUsername's helped me see that.
 
Before I talk about the new results I want to apologize for the inaccurate results I posted before. I was wondering why my benchmarks were so bad with the Nvidia nForce and Microsoft standard IDE drivers and I found that OCZ's Agility 3 and Vertex 3 SSDs have an issue when used on Nvidia chipsets. When the link speed is set to SATA III speeds, 6 Gbps, they actually give you SATA I speeds. I had to go in and change the link speed to SATA II speeds, 3 Gbps to get accurate reults.
 
Looking at the new results you can see that the Microsoft AHCI driver performs better at reading and writing smaller files but the Nvidia and standard IDE drivers perform better reading larger files due to the bottleneck issue. This means the Nvidia drivers will load large files faster but the Jmicron driver would load small files faster. In normal usage though you would be hard-pressed to notice the difference.
 
Clearly benchmarks don't tell the whole story and they provide a lot of information you have to figure out. They also seem to concentrate on what they think is important. For example, at first glance the ATTO test makes it look like the Nvidia driver is the clear winner while AS SSD shows the AHCI driver on the Jmicron controller the victor. Do the results change my opinion on what I am going to use? No they don't. But I have learned a lot about the options that are available. Each driver and controller has its strengths and its weaknesses and arguments can be made for any of them. Really its just going to come down to personal taste.
 
Personally I want to have TRIM so I'm going to continue using the Jmicron controller with the Microsoft AHCI driver for a while longer. It has proven to me that it is a viable option. For me it gets better all around performance than the Microsoft IDE driver which is the only other one to provide TRIM. The read speed of large files may be a little worse, but let's face it, is it large enough to really notice?
 
This is just my experience and my opinion for my good old 790i build. You may get different results based on your SSD and find that using the Nvidia drivers is the way you want to go because you only use your drive for the OS or maybe to load games faster but don't write to it very often so TRIM isn't a factor to you. How you use it may push you to go a different way than me and that's ok. Do what's best for you. I just hope the post provides some information for people looking to find out what their options are and how they may compare to each other. 
 
*Each set of screenshots start with the Jmicron controller with the Microsoft AHCI driver, then the nForce drivers on the native SATA port, and then the standard dual channel PCI IDE driver also on the native SATA port

After you connected the SSD to the add-on card did you go into your BIOS -> Advanced BIOS Features -> Hard Disk Boot Priority and make sure the SSD is at the top of the list? If it is not then make sure you change it to  #1.
If the SSD is the drive at the top of the list and it is still not booting up Windows then I suspect you have a driver issue. Either connect your SSD back to the Jmicron port and boot into Windows to load the add-on card drivers or try another fresh Windows installation and make sure you select the option to load 3rd party SCSI/RAID drivers. I haven't done a fresh install with Windows 8 yet so I'm not sure exactly when the option appears but it should be around the start of the installation.
Also double check the add-on card BIOS to make sure the settings are correct there. You mentioned it does see the drive but something could be off.

Sorry I have been fairly busy as of late and have not had a chance to reply. I highly doubt the SSD is defective. As you mentioned it wouldn't work connected directly to the motherboard's SATA ports. Just seems as if the add-on card and SSD won't play nice with each other.
 
When you used the card with the HDD did you boot off of the HDD? Was it on your 790i board? Did you use multiple HDDs in a RAID setup? Are you currently trying with the SSD and HDD both connected to the add-on card?