SSD laptop drives 'slower than hard disks'

Im not sure I competely believe this, after all its still commonplace to see laptops sold with 5400rpm drives.

Hi there

Here we go again

It's amazing how in these sort of articles written by people who should know better just blame the new technology without looking for the underlying causes of the problem.

SSD devices CAN (and ARE) FAR FAR faster. - Period. No if's No Buts they JUST ARE due to the specifications etc. Even the most blinkered cynic can't break the Laws of Physics.

Now the trick is in order to USE the inherently faster speed you need to ensure that 4 components have been correctly designed or you will get an effect of trying to empty a 100 litre tanks with just a pinhead size hole as the outlet.

1) The O/S can actually handle the faster speed -- this means the I/O sub system can service and process the Interrupts fast enough to avoid "Disk waits" which then entails "I/O retries" and longer wait times as the whole I/O request has to be re-executed.

2) The Hardware bus speed is up to the speed -- if you just bolt the SSD to a typical Mobo you won't get the performance increase you are looking for.

3) The actual hardware driver is optimally designed for transferring I/O to the actual device in "Native SSD mode" rather than "Classical ATA standard mode"

4) The Bios (which Windows calls to actually perform the physical I/O to read and write the data streams) is also optimally written. Some older Bioses won't be able to take advantage of the superior SSD and ATA 3.0 specifications so your device will appear to the machine as a "bog standard" ATA device. This in conjunction with point 1) will actually in some cases make your device seem SLOWER than a decent standard ATA drive. This is NOT because the disk is bad but due to other factors.

As these devices become more common (they are good for laptops -- no moving parts, less power etc) the I/O routines, device drivers and Mobo Bioses will be updated. Once these are all in place even now you should start to see at leas a 2X improvement in Disk performance - and as poor disk performance is usually the main cause of the vast majority of "unpleasant" computing experience users will notce very quickly the advantages of using SSD's.

Cheers
jimbo

There are SOME SSDs which are really slow, due to the controller and the architecture. If you take a first generation SSD with a Jmicron controller, it is slower than a conventional HDD - BUT only in small 4kb random reads and writes.

However, do sequential reads and writes, and ANY SSD will beat a hard drive hands down.

sigh... the problem with the internet is that anyone and everyone suddenly becomes an expert.

Captain Zero said:

This is total nonsense. Even a SLC would vastly out-perform a laptop HD. Bah, had this argument too many times.

Hi there
I agree -- which is why I've put some proper Engineering with my answer. As you say there are so many people who if they see something on the Internet they just assume its "Gospel" and therefore must be true.

A lot of the so called "tech" magazines are the worst -- badly conceived "performance tests" with NO theory behind them etc etc.

Some laptop HD's actually aren't too bad but laptops aren't designed for performance breaking speed etc. There's a compromise between cheapness, ruggedness and portability. These days cheapness is often the deciding factor.

Cheers
jimbo