Hi guys, my friend tell me that i should get a Sata 3 hard drive with the new rig i plan to buy soon, but im not really conviced that a smart move. I already have 4 Sata 2 hard drive, and buying another drive isin't really fitting in my budget. Now i know all about the speed difference between the two (3 Gb/s vs 6 Gb/s), but almost every web site i look people says that we can't even saturate Sata 2 HDD at the momment. Then, i watched a video where a guy was benchmarking a Sata2 with 32 mo of cache and Sata 3 with 64 mo of cache, wich appear to be almost twice as fast, but i suspect the cache is the culprit here.

Am i right? What's your advice?

What are top speeds of HDD drives? 150 MB/s? If so then 150*8 = 1200 Mb/s which is well below 3000 Mb/s of Sata2 limit. So imho upgrading to Sata3 won't gain much for HDD.

If you want to buy a new hard-drive, then buying a SATA3 one would be nice, but if you don't need a new one, then keep using your SATA2 ones

I would really recommend a super-fast SSD to install the OS onto, but only if you've got the money to spare.

It can be confusing to compare different speeds in this arena, because there's so many different standards -- the whole 1000 vs 1024 debate...

Hard-drive manufacturers use decimal prefixes (1000) instead of binary prefixes (1024).

Sata 2 (AKA SATA 3Gb/s) actually achieves 2.4 Gb/s, which is 2.4*1000*1000*1000 bits/s, which is 300000000 bytes/second, which according to a hard-drive manufacturer is 300MB/s, but according to a programmer is 286MiB/s.

I have a SATA3 SSD with speeds of 550MB/s (really 525MiB/s), but it's connected to my SATA2 motherboard, so it runs at almost half speed... Despite that, it's still faster than any hard-drive I've ever used previously

I would really recommend a super-fast SSD to install the OS onto, but only if you've got the money to spare.

I have a SATA3 SSD with speeds of 550MB/s (really 525MiB/s), but it's connected to my SATA2 motherboard, so it runs at almost half speed... Despite that, it's still faster than any hard-drive I've ever used previously

I definitely agree with getting an SSD if you're going SATA3. I recently upgraded to a 256Gb 550MB/s SSD connected via SATA3, and Windows 7 has gone from taking over a minute to boot to just a few seconds.

I have a SATA3 SSD with speeds of 550MB/s (really 525MiB/s), but it's connected to my SATA2 motherboard, so it runs at almost half speed... Despite that, it's still faster than any hard-drive I've ever used previously

I hope you're getting a SATA 3 mobo soon, those 500MB/s SSDs cost an arm and a leg...

FWIW: if a person has generic HDDs, gigabit Ethernet is still fast enough to generally access the drives at pretty much full-speed over a LAN (not that hard, most newer MOBOs and routers/switches come with it), and 1GBe is still a bit slower than SATA.

so, yeah, unless one has an SSD, SATA 2 vs 3 wont likely make much difference.

No spinning drive will saturate even Sata 2.

Sata 3 is really only needed for SSD drives, so I'd say that if you want an SSD boot drive now or in the future, get a motherboard that supports Sata3, but you don't have to get the drive right now if you can't afford it.

You young whippersnappers! When I was a boy we had punchcards and pencils!

...and we were grateful!


I think SATA 3 is just a little bit early, for the reasons already mentioned. I'm actually kind of stoked about the idea of SSD becoming the new standard, but that's still some time away. I feel like by the time I'm ready to have an SSD for home use I'm probably going to be using a new mobo anyway, so I don't see any reason to upgrade to SATA 3 at present. That said, if I do buy a new mobo then SATA 3 support is one of the things I'd look at when I make my decision. I'm not ready to spend more than about $20 on it, though, just because I don't expect to need it any time soon.

I have a SATA3 SSD with speeds of 550MB/s (really 525MiB/s), but it's connected to my SATA2 motherboard, so it runs at almost half speed... Despite that, it's still faster than any hard-drive I've ever used previously

Funny, that's word by word what I was going to write. SSD to SSD copy on SATA2 on my computer delivers around 280-290 MB/s according to what Windows Explorer says, which is pretty much the theoretical maximum minus the latency the driver takes to send commands and such.

That's stunning, because usually when someone tells you "300" it means "yeah, you know, 150 in the regular case, 180 if you are lucky... but in theory, it can do 300, but of course only if [long list of unrealistic conditions]". Think of an "extreme speed 32GB/s" USB stick. You can be really happy if you get 10 out of the promised 32GB/s, and half that when writing.

Getting 280-290 out of a promised 300 in everyday operation is just fucking awesome.

So, while SSD is apparently really limited by the bus, does it matter? Not really, it's still incredibly fast (...and I assume it's probably even an advantage for the device's lifetime -- if data comes slower than the device can handle, it can probably do a much better job at caching, coalescing writes, and rearranging blocks and whatever it does. Well, I don't know, but maybe... is my thinking).

I hope you're getting a SATA 3 mobo soon, those 500MB/s SSDs cost an arm and a leg...

Not really, no. A 256G SATA3 solid state disk costs about twice as much as a 1T conventional disk, granted. But compare that to what a graphics card or a CPU costs, and consider what it gives you. I have two Vertex4 256G (and no normal harddisk other than the one I put in the mobile rack for backup), and it's the best ever investment I made.

POST beep to Windows 7 login in 8 seconds, no noticeable delay when starting any "normal" program, roughly 100% faster build times, and 3-4 seconds for "ugly fat pigs" to start up, such as OpenOffice (instead of 45-50 seconds). And that's without silly tricks like preloaders.

Now of course if you need 2-3 terabytes of storage, SSD does come a bit expensive... but if you're a bit sensible with the junk you hoard, you can live perfectly happily even with a single 128G SSD. There's always NAS for very little $$$ if you have the need to store a few terabytes of MP3s or movies, and access time really doesn't matter at all for these.

I'm using a NAS from WD, which apart from coming configured as dumb as possible (parking head every 10 seconds), works very well. Plug in cable, works. 5 mins of setup to make it behave less dumb, and you're done. Plus, you have an ultra-low power Debian server you can run Subversion (or Git, if you will) on, for free.

Ok, thx for your replies, i think ill wait before buying a new drive, already have 3TB . Now, im considering buying a 64 go ssd, but i fear it might be to small for Win 7, my friend tell me is windows folder is 22go in size, but i find that hard to believe. Im still on XP atm, but have win 7 installed in one of my wmware machine, and it only take 8. Are windows update really that big ???