How much does SSD performance scale with size?

[TreVader]

I just ordered a 15" rMBP with only 512GB SSD and i'm wondering what kind of performance penalty (if any) I will pay for not going 1TB. I would hope not much, if it's a lot I might end up just ordering a full 1TB.

 

[TemjinGold]

Not much once you get past like 250 gigs.

 

[Rubycon]

The main advantage of 1TB is you can store 512GB on it and still have great performance. If both cases you have 100GB, you would never see any difference. Benchmarks would likely be similar as well.

 

[birthdaymonkey]

Beyond the 240-256GB tier, there isn't much (if any) performance improvement.

My 512GB 840 Pro actually benches worse in some tests than the 256GB model.

 

[TreVader]

ok good, I was starting to consider re-ordering it with the 1TB just for the improved performance.

I mean, the idea is to have the fastest possible laptop I can get (that's a mac). I don't really need the 1TB because I really only expect to have ~300GB on it at any one time. I can always get a Thunderbolt drive for storage.

 

[TreVader]

Its crazy to me how things change. The last Laptop I bought before the macbook air i'm on now was an inspiron 8200 with a 1.6Ghz P4 with 256MB Ram and a MASSIVE 80GB HDD. I was like whaaaat nobody is gonna need that much ram or that much space. Now you can't even buy a computer with less than 2GB ram.

 

[jiffylube1024]

Beyond the 240-256GB tier, there isn't much (if any) performance improvement.

My 512GB 840 Pro actually benches worse in some tests than the 256GB model.

+1.

Generally there's a boost going from 128mb to 256 mb, but after that it's negligible.

 

[BFG10K]

Write performance can increase dramatically with bigger sizes, especially on TLC drives. If you regularly copy files to your SSD, this can make a difference.

 

[ShintaiDK]

You need to check with every single SSD. For example with Crucial M500:
http://www.crucial.com/store/ProductMarketing_m500.aspx

There is no difference between 480GB and 960GB. But a difference if you go below.

 

[sub.mesa]

This has to do with both interleaving (most SSD controllers use 8 channel with 2 die per channel interleaving; 16-way interleaving in total) and with SATA bottlenecks. Interleaving is probably best described as RAID0; a single SSD is actually a RAID0 of several flash components. The one thing it cannot improve is single queue read IOps, which remains at single channel performance (~25MB/s).

However, larger SSDs may have just as much interleaving as lower capacity SSDs, because larger chips are used instead of more interleaving. If there would be PCIe SSD controllerchips with more than 16-way interleaving, the speeds could very well continue to scale; into the multi-GB per second quite easily.

 

[Rubycon]

This has to do with both interleaving (most SSD controllers use 8 channel with 2 die per channel interleaving; 16-way interleaving in total) and with SATA bottlenecks. Interleaving is probably best described as RAID0; a single SSD is actually a RAID0 of several flash components. The one thing it cannot improve is single queue read IOps, which remains at single channel performance (~25MB/s).

However, larger SSDs may have just as much interleaving as lower capacity SSDs, because larger chips are used instead of more interleaving. If there would be PCIe SSD controllerchips with more than 16-way interleaving, the speeds could very well continue to scale; into the multi-GB per second quite easily.

Precisely why 3GB/S writes with arrays are possible and much cheaper than a similar sized RAMSAN, for example.

 

[aigomorla]

Not much once you get past like 250 gigs.

+1

in the 240-256gig class, typically all lanes are open on the SSD...
They neuter the low class ones with half the lanes.

Precisely why 3GB/S writes with arrays are possible and much cheaper than a similar sized RAMSAN, for example.

RUBY!! i missed ya... havent seen u active in a while...

You need to check with every single SSD. For example with Crucial M500:
http://www.crucial.com/store/ProductMarketing_m500.aspx

There is no difference between 480GB and 960GB. But a difference if you go below.

:O so they neutered the 240gig class??

That kinda blows, because the C300 had full lanes open at 256,

 

[Hellhammer]

:O so they neutered the 240gig class??

That kinda blows, because the C300 had full lanes open at 256,

Micron/Crucial switched to 128Gbit NAND, so the number of dies halved in all capacities, which in turn reduced performance but allowed higher capacities.