The OCZ Vector 180 (240GB, 480GB & 960GB) SSD Review
by Kristian Vättö on March 24, 2015 2:00 PM EST- Posted in
- Storage
- SSDs
- OCZ
- Barefoot 3
- Vector 180
AnandTech Storage Bench - Light
The Light trace is designed to be an accurate illustration of basic usage. It's basically a subset of the Heavy trace, but we've left out some workloads to reduce the writes and make it more read intensive in general.
| AnandTech Storage Bench - Light - Specs | ||||||||||||
| Reads | 372,630 | |||||||||||
| Writes | 459,709 | |||||||||||
| Total IO Operations | 832,339 | |||||||||||
| Total GB Read | 17.97 GB | |||||||||||
| Total GB Written | 23.25 GB | |||||||||||
| Average Queue Depth | ~4.6 | |||||||||||
| Focus | Basic, light IO usage | |||||||||||
The Light trace still has more writes than reads, but a very light workload would be even more read-centric (think web browsing, document editing, etc). It has about 23GB of writes, which would account for roughly two or three days of average usage (i.e. 7-11GB per day).
| AnandTech Storage Bench - Light - IO Breakdown | |||||||||||
| IO Size | <4KB | 4KB | 8KB | 16KB | 32KB | 64KB | 128KB | ||||
| % of Total | 6.2% | 27.6% | 2.4% | 8.0% | 6.5% | 4.8% | 26.4% | ||||
The IO distribution of the Light trace is very similar to the Heavy trace with slightly more IOs being 128KB. About 70% of the IOs are sequential, though, so that is a major difference compared to the Heavy trace.
| AnandTech Storage Bench - Light - QD Breakdown | ||||||||||||
| Queue Depth | 1 | 2 | 3 | 4-5 | 6-10 | 11-20 | 21-32 | >32 | ||||
| % of Total | 73.4% | 16.8% | 2.6% | 2.3% | 3.1% | 1.5% | 0.2% | 0.2% | ||||
Over 90% of the IOs have a queue depth of one or two, which further proves the importance of low queue depth performance.
The Barefoot 3's focus has always been sustained rather than peak performance and that's visible in our Light trace. It's not slow by any means since most drives are within a 10% margin (excluding the 850 Pro and Neutron XT), though.
The same applies to latency where most drives are essentially on par with each other.
While the 850 Pro does very well when it comes to performance, it's also the most power hungry, whereas the Vector 180 at smaller capacities is again easily the most power efficient drive.
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nathanddrews - Tuesday, March 24, 2015 - link
This exactly. LOLSamus - Wednesday, March 25, 2015 - link
Isn't it a crime to put Samsung and support in the same sentence? That companies Achilles heal is complete lack of support. Look at all the people with GalaxyS3's and smart tv's that were left out to dry the moment next gen models came out. And on a polarizingly opposite end of the spectrum is Apple who still supports the nearly 4 year old iPhone 4S. I'm no Apple fan but that is commendable and something all companies should pay attention too. Customer support pays off.Oxford Guy - Wednesday, March 25, 2015 - link
Apple did a shit job with the white Core Duo iMacs which all develop bad pixel lines. We had fourteen in a lab and all of them developed the problem. Apple also dropped the ball on people with the 8600 GT and similar Nvidia GPUs in their Macbook Pros by refusing to replace the defective GPUs with anything other than new defective GPUs. Both, as far as I know, caused class-action lawsuits.Oxford Guy - Wednesday, March 25, 2015 - link
I forgot to mention that not only did Apple not actually fix the problem with those bad GPUs, customers would have to jump through a bunch of hoops like bringing their machines to an Apple Store so someone there could decide if they qualify or not for a replacement defective GPU.matt.vanmater - Tuesday, March 24, 2015 - link
I am curious, does the drive return a write IO as complete as soon as it is stored in the DRAM?If so, this drive could be fantastic to use as a ZFS ZIL.
Think of it this way: you partition it so the size does not exceed the DRAM size (e.g. 512MB), and use that partition as ZIL. The small partition size guarantees that any writes to the drive fit in DRAM, and the PFM guarantees there is no loss. This is similar in concept to short-stroking hard drives with a spinning platter.
For those of you that don't know, ZFS performance is significantly enhanced by the existence of a ZIL device with very low latency (and DRAM on board this drive should fit that bill). A fast ZIL is particularly important for people who use NFS as a datastore for VMWare. This is because VMWare forces NFS to Sync write IOs, even if your ZFS config is to not require sync. This device may or may not perform as well as a DDRDRIVE (ddrdrive.com) but it comes in at about 1/20th the price so it is a very promising idea!
ocztosh -- has your team considered the use of this device as a ZFS array ZIL device like i describe above?
Kristian Vättö - Tuesday, March 24, 2015 - link
PFM+ is limited to protecting the NAND mapping table, so any user data will still be lost in case of a sudden power loss. Hence the Vector 180 isn't really suitable for the scenario you described.matt.vanmater - Wednesday, March 25, 2015 - link
OK good to know. To be honest though, what matters more in this scenario (for me) is if the device returns a write io as successful immediately when it is stored in DRAM, or if it waits until it is stored in flash.As nils_ mentions below, a UPS is another way of partially mitigating a power failure. In my case, the battery backup is a nice to have rather than a must have.
matt.vanmater - Tuesday, March 24, 2015 - link
One minor addition... OCZ was clearly thinking about ZFS ZIL devices when they announced prototype devices called "Aeon" about 2 years ago. They even blogged about this use case:http://eblog.ocz.com/ssd-powered-clouds-times-chan...
Unfortunately OCZ never brought these drives to market (I wish they did!) so we're stuck waiting for a consumer DRAM device that isn't 10+ year old technology or $2k+ in price tag.
nils_ - Wednesday, March 25, 2015 - link
Something like the PMC Flashtec devices? Those are boards with 4-16GiB of DRAM backed by the same size of flash chips and capacitors with a NVMe interface. If the system loses power the DRAM is flushed to flash and restored when the power is back on. This is great for things like ZIL, Journals, doublewrite buffer (like in MySQL/MariaDB), ceph journals etc..And before it comes up, a UPS can fail too (I've seen it happen more often than I'd like to count).
matt.vanmater - Wednesday, March 25, 2015 - link
I saw those PMC Flashtec devices as well and they look promising, but I don't see any for sale yet. Hopefully they don't become vaporware like OCZ Aeon drives.Also, in my opinion I prefer a SATAIII or SAS interface over PCI-e, because (in theory) a SATA/SAS device will work in almost any motherboard on any Operating System without special drivers, whereas PCI-e devices will need special device drivers for each OS. Obviously, waiting for drivers to be created limits which systems a device can be used in.
True PCI-e will definitely have greater throughput than SATA/SAS, but the ZFS ZIL use case needs very low latency and NOT necessarily high throughput. I haven't seen any data indicating that PCI-e is any better/worse on IO latency than SATA/SAS.