Ssd+hdd or sshd
Ok so basically i have a notebook with a 500gb hdd with 5400rpm. My dilema is what should i fit in it, a new hdd with 7200rpm and a ssd with 120gb or a sshd with 5200rpm? Which one is faster? I mention that now i have very big problems with loading anything, even when i try to open a folder it lags for about 5 seconds. I want to improve the quality in booting and playing a game (csgo, which is not that demanding for resources). So, where should i focus my attention? On the combo ssd+hdd or sshd?
If the laptop can take both, the SSD + HDD is always preferable. The flash cache on the SSHD is typically only 8 GB (some are 16 GB), and used only to cache small files (which HDDs are slowest at reading). So even when reading cached data the speed will typically top out at 30-60 MB/s (vs about 1 MB/s for the HDD). A SSD hits the same speeds for small files, but can go faster than 500 MB/s for large files. The cache on the SSHD also does nothing for writes - it will behave just like a HDD when writing data.
I'd second USAFRet's recommendation for at least a 250 GB SSD. The 120 GB models typically use half the number of flash dies, and are slower. And Windows is getting to the point where 120 GB may be too small for many people (the Windows folder on my laptop is currently at 46.5 GB). IMHO a bigger SSD is more important than a 7200 RPM HDD (only 33% faster than a 5400 RPM HDD).
If you want the best of both worlds, there is a way to repatriation your SSD so it'll operate as both a boot drive and as a flash cache for the HDD (basically turn a regular HDD into a SSHD). But the process is rather convoluted and involved (and not supported by all hardware), so I wouldn't recommend it unless you're really hardcore about getting the most performance possible.
like1337, good question. Read this article to give you a better idea what the different types of drives do and their best uses. Let us know if we can answer any questions; we're here to help.