Should I repair or buy a new one?

@Louis - Remember this is an older Core 2 Duo. I wouldn't throw that much into it. Besides I'm sure a Seagate hybrid or even a Western Digital dual drive will offer more than enough zip here.

Nope. I have tried SSHD's. They are garbage. They only have 8-16GB cache and it does nothing to big applications. I'd rather have my SSD over another SSHD. My other reason for going this route is I own a laptop that I feel the money into a SSD was worth it.

@Nick - We have over 200 of these drives in the field in i5 & i7 MacBook Pro systems with great success. We had nothing but problems doing a dual drive setup (HD/SSD) across a few different series. Sure a dual SSD would likely have been better but we needed the space and didn't want (still don't) the costs of the larger SSD's we would have needed. Your performance can very depending on what app or size of the data files being used. We do very large CAD and other graphical stuff. SSHD's are much better than older HD's and given the size limits & price of the SSD's I can't see many people trying what we do with them. I should also point out the constant churning of files also wears out a SSD much faster than a HD. We've seen that as well in a few of our desktop systems.

Okay, key me offer some clarification. Yes, they can be good but due to the limited SSD cache they tend to vary heavily. I used mine in a machine I use for semi heavy applications and light stuff, so that's probably why. I also noticed the read/write speeds are worse then normal hard drives too. While they aren't complete junk, they tend to only really work for pure lightweight users. If you even border this in the slightest they just give you the finger and run like a normal hard drive(if not worse then a normal drive). I use a Dell Latitude E6540.

SSHDs are good mostly for bootup. I use them just because they cost an additional ten bucks and when customers see their laptop boot way faster than it did when they bought it, it gives them that impression that we did a kickass job - even though the rest of the machine will be just as slow as it was before! But it is worth the ten dollar investment to give someone the overall feel that we are the best.

But yeah for regular performance they are $@$*. I only recommend investing this much into an old machine because you can use SSDs in newer machines as well(besides Retina & Air), and even in a PC if you decide to go that route. The storage medium is the real bottleneck in all modern machines so getting rid of as much of that as possible will make the biggest difference.