Ssd Size - Explain It To Me

It strange that corsair advertise their ssd`s as 60gb, 120gb, 240gb, ect , and other manufactures as 64gb, 128gb, 256gb.

Are both manufactures drives the same size, but one is quoting, the size including wear leveling space, ect, and the other is not.

I am not talking about the formatted size, and some capacity being lost to the fat table.

will an corsair 60gb ssd show the same free space after formatting as an 64gb ssd

anybody know.

 

No. SSDs have overprovisioning which is a certain amount of NAND dedicated to the ssd itself and not recognizable in the total available memory size to the user. For example, all ssds in the area of 100-128Gb contain 128Gb NAND. The question is mainly whether they contain 7% overprovisioning or 28% overprovisioning

Firmware itself will also grab an average of 9Gb more space once formatted for files leaving a 100Gb drive with only 92Gb free space.

The overprovisioning allows the drive to run much better, cuts down on performance degradation and in most opinions, will extend the life of the drive significantly.

I have tested the OWC Pro RE (28%) 100Gb and the OWC Pro 120Gb and both have the exact same performance results.

 

so... why do some drives have more overprovisioning than others despite having the same total nand?

is it just inefficient use of nand space, or does the extra overprovisioning have any benefits?

 

From what I know, over-provisioning can benefit performance and aid wear-leveling.

 

so you mean a drive with 28gb of overprovisioning can benefit performance/aid wear leveling more than one that has 14gb of overprovisioning?

 

Thats what i thought, I had heard that you should leave 20% of your sdd free for wear-levelling , but if the ssd already includes this reserved space, you can use 100% of the free space and still have wear-leveling.

It does seem something of an marketing failure, when the general consumer had the choice of two ssd, one 60gb and the other 64gb, they are going to bu the 64gb one.

So do the 64gb ssd, not have any wear-leveling space reserved, or are they just misleading the customers on the size of the ssd.

 

Not necessarily, it depends on the drive's controller.

 

Is there any way to unlock the extra space?

 

To answer your question in the most basic terms--not all SSD are created equally.

For example, what you're asking is the equivalent of why some automobile tires last 50,000 miles while others at the same cost last only 30,000 miles. The result is what one manufacture deems most important for the consumer. In this case, a better cohesion to the road, verses a lower rolling resistance.

Sure you can buy a tire that lasts 50,000 or even 70,000 miles, but it will be hard as a cue ball and ride harsher. On the other hand, a performance tire will have a higher rubber content and give you greater handling and stopping ability, but will wear much faster. The computer business is no different; and that relationship can be applied to almost any other product as well.

In any event, you as a consumer have to decide which compromise is most important to you, then pick the brand or model that best fills that gap. You should also keep in mind that since no one brand/model can do everything perfectly, when you find one that comes very close, chances are you'll pay an awful lot of money for it.

If one manufacturer decided to spare you a few GB, it's most likely they consider more stability and perhaps more endurance over total storage space. Your Corsair brand/model will undoubtedly have a more stable writing capability than those that give you more GB. Don't get caught up in the numbers, rather, pick the brand/model that fits your specific needs.

 

perfect, now i know to look for the 'lower numbers' since i never get close to filling my drives up

 

Whoa kimosabi, that wasn't my point. Intel for instance, offers the best read speed in the SSD business, but write much slower than most. Nevertheless, they produce drives at 160 GB.

Instead, look for drives that offer the best performance for how you will use your drive.