Performance Vs. Capacity
I really like HDTune Pro. It's a decent canned storage test full of helpful tools. The utility is great for evaluating hard drives, and a little less relevant to SSDs. The software's most prominent feature is its ability to write and read to the entire surface of a storage device. When you're testing rotating media, it's easy to observe speed dropping as measured from the outer to inner tracks. That's just physics. With SSDs, the "surface" is the drive's entire capacity, minus over-provisioning or spare area.
Now, there are good reasons to use HDTune for reviewing SSDs, but there are serious limitations to be aware of as well. Most strikingly, HDTune writes in easily compressible zero-fill data, which isn't particularly useful for testing SandForce's technology. Also, I want more control over how the utility does its job. So, I created my own script-based version to do what I need.
This little tool is especially helpful for testing OCZ's newer offerings because they are able to take the capacity of a given drive and use it in a way that emulates single-level cell NAND in a manner of speaking. We think the mechanism works with faster pages for as long as it can, delaying the use of slower pages. This is why the Vector, Vertex450, Vertex 4, and Agility 4 prefer to write to the faster half of the flash. It's easiest to demonstrate that unique behavior by charting performance over capacity.

Starting with a freshly erased drive, we write to the entire capacity and display our results as a percentage of the capacity. I separate the 240 GB SSD into sequential chunks 1/200th of the total capacity. Then, each segment's average throughput is displayed as a data point representing 0.5% percent of the "surface". In this case, the Vertex 3.20 and Vector 150 are the same size (240 GB), while the Vertex 450 and Vector are 256 GB. The larger the addressable capacity, the more bytes it takes to equal one 0.5% chunk.
We want to write sequentially, so we're sticking with 1024 KB access sizes and a queue depth of one. Higher queue depth activity isn't always truly sequential in the strictest sense of the word.
From the beginning, OCZ's Vector, Vector 150, and Vertex 450 are neck and neck until just past the 50% mark. After that, the Vector 150 extends even further before dropping into sub-200 MB/s territory. Once all of the fast pages are gone, the drive has to write to the slower-to-program pages that comprise half of the flash. Once the speed stabilizes again, the Vector 150 outpaces (by a few MB/s) the Vector, which in turn is above the Vertex 450.
Also included in our chart is the Vertex 3.20. OCZ's 240 GB SandForce-based drive is being fed random data. But notice the lack of performance variation as the drive is written. Also, the Vertex 3.20 falls right around the average speed of OCZ's Indilinx-infused SSDs if you consider their whole capacity. This is a good reality check that represents the behavior of most other drives.
Theoretically, if we were to fill 60% percent of the drive with real files (say an operating system and a few games), the SSD would write that data as quickly as possible to the faster pages. Then, over time, it'd shuffle around that data, freeing up some portion of the remaining faster pages for new tasks. We can't say for certain that the process works this way; OCZ is tight-lipped about its mechanism, and we're left with educated guesses.
So why does the Vector 150 maintain its excellent performance longer than the other two Barefoot-based SSDs? The answer lies in the additional over-provisioning. The Vector 150 uses 16 GB more over-provisioning than the Vector and Vertex 450. Sixteen gigabytes is 6.25% of 256 GB, so it's possible that the Vector 150 can go around 6% deeper without slowing down to sub-200 MB/s levels.
- Meet The Vector 150, OCZ's New Flagship SSD
- Test Setup and Benchmarks
- Results: 128 KB Sequential Performance
- Results: 4 KB Random Performance
- Results: The Vector 150's Performance Quirks
- Results: The Vector 150's Performance Quirks, Continued
- Results: Tom's Hardware Storage Bench
- Results: Tom's Hardware Storage Bench, Continued
- Results: PCMark 7 And PCMark Vantage
- Results: File Copy Performance
- Results: Power Consumption
- We Love Performance, But Also Want More Value
I just hope the quality increased. Only because at my last job we had used Vertex 3s for all of our work stations and they one by one started having random issues, from not being detected to wiping the partitions.
I like OCZ because they help lower the price of SSDs but there has to be quality behind the price as well.
I just hope the quality increased. Only because at my last job we had used Vertex 3s for all of our work stations and they one by one started having random issues, from not being detected to wiping the partitions.
I like OCZ because they help lower the price of SSDs but there has to be quality behind the price as well.
My impression is that OCZ was hit hard by the Sandforce issues, partially as a result of being an early adopter. Their newer drives seem to be reliable.
Awesome catch! The 520 seems to have the right bar length, but the label from the Intel 510. I'll sort that out, but that's a genuine not-my-fault problem. One of the very few. I can blame Excel 2013 with confidence, but kudos for the eagle eye.
The random write bar is correct though; the SandForce-based 520, 525, and Intel 530 each pull down more random write IOps than read with incompressible data.
Regards,
CR
Early on yes, but the 2nd gen SF drives really are pretty darn stable now. OCZ has had solid top tier releases since the Vertex 4. I own Vertex 4 and Vector, will probably get a 150. Hands down the worst thing they ever did was try budget/value offerings like the Petrol. I don't think there is any reason for fanboism, I own Samsung and OCZ drives and all work happily together.
cryan, $135 would sure be nice, but as usual real-world prices
can spoil the attractiveness of a new product. Scan.co.uk has
the 120GB Vector 150 listed for 115 UKP (ie. about 35% more than
the stated RRP), making it 10 UKP more than the tried & trusted
840 Pro; worse, it's a whopping 26 UKP more than the Vertex 450
(even the 120GB Vertex3 MAX IOPS is 18 less). Scan has its own
double-irony though, as they also list the original Vector 128GB
as a factory refurb (FR) for 70.
256GB Vertex4 FR for 119, the 256GB Vector FR for 131, the 512GB
Vertex4 FR for 215 and 512GB Vector FR for 233 (I bought one of
the FR 512GB Vertex4s, performing splendidly as an AE cache drive).
Best price I could find for the Vector 150 120GB was 100 UKP on
dabs.com. SSDs continue to be a tad expensive here. I was hoping
we'd see 240GB/256GB below 100 UKP this year, but sadly not.
Prices were certainly heading that way a year ago, with the 830
256GB going for as low as 119 UKP, but then everything went whacko
back in Feb this year as prices jumped back up again.
Amdlova writes:
> time to upgrade from vertex 4 to 150
It's unlikely you'd notice any real-world difference between a
Vertex4 and the Vector 150. The Vertex4 is already pretty quick.
ssdpro writes:
> ... Hands down the worst thing they ever did was try budget/value
> offerings like the Petrol. ...
Indeed! What did you make of the Agility3/4 series though? I bought
an Agility4 128GB for testing; it's not too bad, though HDTach gave
rather wobbly write performance and curiously low read speeds compared
to the numbers reported by AS-SSD which were much higher.
ssdpro writes:
> ... I don't think there is any reason for fanboism, I own Samsung
> and OCZ drives and all work happily together.
Yup, me too. I ended up with a lot of 120GB MAX IOPS units when several
vendors were doing them dirt cheap (no idea why), but I have many
Vertex2Es aswell, all running fine. With the fw updated, the early SF
drives are ok. I have two Vector 256s, a Vector 128, various Vertex4s
and a range of Samsungs (830, 840, 840 Pro). The main difference I've
noticed is that the Samsung units seem to be able to maintain better
and more consistent steady-state read speeds, giving completely smooth
HDTach graphs, eg. here's my 3930K system's 840 250GB:
http://www.sgidepot.co.uk/misc/samsung_840_250GB_HDTach_22-May-2013.gif
Contrast that with my 2700K system's Vector 256GB:
http://www.sgidepot.co.uk/misc/OCZ_Vector_256GB_HDTach_12-Nov-2013.gif
In reality though, I can't tell the difference between them for normal
real-world use. They both load complex apps nice & quick, etc.
Ian.
Waiting for a SATA 4 SSD and then buy it used when cheap (many many years from now).
For now I'm rocking an X25-M SSD, very reliable and quick enough.
cryan, $135 would sure be nice, but as usual real-world prices
can spoil the attractiveness of a new product. Scan.co.uk has
the 120GB Vector 150 listed for 115 UKP (ie. about 35% more than
the stated RRP), making it 10 UKP more than the tried & trusted
840 Pro; worse, it's a whopping 26 UKP more than the Vertex 450
(even the 120GB Vertex3 MAX IOPS is 18 less). Scan has its own
double-irony though, as they also list the original Vector 128GB
as a factory refurb (FR) for 70.
256GB Vertex4 FR for 119, the 256GB Vector FR for 131, the 512GB
Vertex4 FR for 215 and 512GB Vector FR for 233 (I bought one of
the FR 512GB Vertex4s, performing splendidly as an AE cache drive).
Yeah, OCZ didn't give out MSRPs prior to launch. OCZ decided to launch the Vector 150 on the same day and same time as the nVidia 780 ti, so that conflict and a holiday pushed it to today, by which point units were available on e-tailer shelves here in the states, which I'd fully expect to NOT represent UK and European pricing.
To be honest, the Vector 150 is a fine drive, but even here its pricing is just not currently in sync with what I believe most Toms readers would be willing to pay, given the totality of the package.
The 120 GB Vector is less expensive than the 120 GB Vector 150 here at the moment. The retailer I used for pricing has a nasty habit of charging a good deal more for newly launched products though, so it's possible the V150 could come down in price soon, but perhaps not significantly.
Regards,
Christopher Ryan
Nah, they have just run into the limits of SATA3. Sandisk's M.2-based A110 shows that SSDs are still improving beyond what SATA3 allows. It's just that SATA Express adoption has been a bit slow compared to M.2.
The 120 GB Vector is less expensive than the 120 GB Vector 150 here at the moment. ...
Indeed. I can't work out who OCZ thinks would buy the 150. The
existing Vector is already good and much cheaper, or - if one can
locate it - the Vertex4 (both drives behave in the same way re when
more than half the space is written to).
Ian.
People were saying that about SSDs in general 11 months ago,
but prices have risen since Feb this year. Consider: a year ago,
in the UK, the Samsung 830 256GB reached a low of 119 UKP.
Today, at least two generations on (840, 840 EVO, etc.), why do
we still not have a decent mainstream 256GB model for under 100?
It's because vendors don't have to, ie. people are willing to pay more
than that (demand), so prices have actually gone up. The 250GB
EVO is 140 UKP here atm.
Likewise, the Vector 256GB stubbornly remained at 225 UKP and
never went down since its launch, and now it's vanishing from seller
sites because of the 150. Although I can find the 240GB Vector 150
for 170 UKP, this price drop vs. the old Vector is not due to sliding
pricing after the initial Vector launch, it's because of a new product
replacing an old, ie. in the intervening months there's been no point
at which the old Vector was available at a sensible price.
Besides, at this price level I'd rather have the 840 Pro instead, which
is 9 UKP cheaper here just now (161 from Amazon with free shipping).
Ian.