SSD

LukeyKid

im look for a good ssd i have a fair idea whats good or not just to make shur though,

and can someone explain what iops are ? :P

my choice of ssd and if anyone has any other ssd in mind can you try keep it around the 85 euro mark and 120 -128 gb thanks

http://www.scan.co.uk/products/120gb-sandisk-extreme-25-ssd-sata-iii-6gb-s-read-550mb-s-write-510mb-s-23000-iops-83000-iops-max

marco_polo

This would be cheaper with the super saver delivery and is highly reliable. The San Disk also seems pretty decent from reviews, and is cheaper again from amazon too because Scans delivers is quite steep at around £11-12 quid. However I don't know how the San Disk rates for reliability as there are far less of them going around.

IOPS is quite simply a measure of the number of IO operations a drive can perform per second. To be a meaningful comparison you have to know which type of IO operation (or mixture of operations) the specified IOPS number is in referring to, as some operation are much faster than others. The quoted IOPS for drives are usually Random 4K read and random 4K write operation.

So if drive claims a maximum IOPS of 85,000 4K write operations per second it quite literally means it can write 85,000 4K sized blocks to a random location on the disk every second under perfect conditions.

While the san disk above quotes a maximum sequential read speed of 500 Mbps, if it were restricted to only doing much slower random (4k) reads (at 23000 IOPs) its maximum transfer speed in that case would be, using the formula MBps = (IOPS * KB per IO) / 1024), roughy 89 Mbps (23000 * 4) / 1024)

LukeyKid

marco_polo wrote: »

This would be cheaper with the super saver delivery and is highly reliable. The San Disk also seems pretty decent from reviews, and is cheaper again from amazon too because Scans delivers is quite steep at around £11-12 quid. However I don't know how the San Disk rates for reliability as there are far less of them going around.

IOPS is quite simply a measure of the number of IO operations a drive can perform per second. To be a meaningful comparison you have to know which type of IO operation (or mixture of operations) the specified IOPS number is in referring to, as some operation are much faster than others. The quoted IOPS for drives are usually Random 4K read and random 4K write operation.

So if drive claims a maximum IOPS of 85,000 4K write operations per second it quite literally means it can write 85,000 4K sized blocks to a random location on the disk every second under perfect conditions.

While the san disk above quotes a maximum sequential read speed of 500 Mbps, if it were restricted to only doing much slower random (4k) reads (at 23000 IOPs) its maximum transfer speed in that case would be, using the formula MBps = (IOPS * KB per IO) / 1024), roughy 89 Mbps (23000 * 4) / 1024)

well im from ireland so the super saver deliver doesnt apply to me and i dont really mind the deliver charge :L and thanks alot really good explaination and so that means the the sandisk ssd max transfer speed is around 324 mBps thats pretty fast ha :L thanks for the help

marco_polo

I live here too and have had loads of stuff delivered for free, it is just not explicitly stated on the product pages

EDIT: I just realised I linked to the wrong San disk version on amazon, it a completely different SSD, so you can ignore that as the Extreme model is actually £90 there.