Random Read Performance

One of the major changes in our 2015 test suite is the synthetic Iometer tests we run. In the past we used to test just one or two queue depths, but real world workloads always contain a mix of different queue depths as shown by our Storage Bench traces. To get the full scope in performance, I'm now testing various queue depths starting from one and going all the way to up to 32. I'm not testing every single queue depth, but merely how the throughput scales with the queue depth. I'm using exponential scaling, meaning that the tested queue depths increase in powers of two (i.e. 1, 2, 4, 8...). 

Read tests are conducted on a full drive because that is the only way to ensure that the results are valid (testing with an empty drive can substantially inflate the results and in reality the data you are reading is always valid rather than full of zeros). Each queue depth is tested for three minutes and there is no idle time between the tests. 

I'm also reporting two metrics now. For the bar graph, I've taken the average of QD1, QD2 and QD4 data rates, which are the most relevant queue depths for client workloads. This allows for easy and quick comparison between drives. In addition to the bar graph, I'm including a line graph, which shows the performance scaling across all queue depths. To keep the line graphs readable, each drive has its own graph, which can be selected from the drop-down menu.

I'm also plotting power for SATA drives and will be doing the same for PCIe drives as soon as I have the system set up properly. Our datalogging multimeter logs power consumption every second, so I report the average for every queue depth to see how the power scales with the queue depth and performance.

Iometer - 4KB Random Read

Random read performance at small queue depths has never been an area where the Vector 180 has excelled in. Given that these are one of the most common IOs, it's an area where I would like to see improvement on OCZ's behalf.

Iometer - 4KB Random Read (Power)

Power consumption, on the other hand, is excellent, which is partially explained by the lower performance. 

Samsung SM951 512GB

Having a closer look at the performance data across all queue depths reveals the reason for Vector 180's poor random read performance. For some reason, the performance only starts to scale properly after queue depth of 4, but even then the scaling isn't as aggressive as on some other drives. 

Random Write Performance

Write performance is tested in the same way as read performance, except that the drive is in a secure erased state and the LBA span is limited to 16GB. We already test performance consistency separately, so a secure erased drive and limited LBA span ensures that the results here represent peak performance rather than sustained performance.

Iometer - 4KB Random Write

In random write performance the Vector 180 does considerably better, although it's still not the fastest drive around. 

Iometer - 4KB Random Write (Power)

Even though the random write performance doesn't scale at all with capacity, the power consumption does. Still, the Vector 180 is quite power efficient compared to other drives.

Samsung SM951 512GB

The Vector 180 scales smoothly across all queue depths, but it could scale a bit more aggressively because especially the QD4 score is a bit low. On a positive side, the Vector 180 does very well at QD1, though.

AnandTech Storage Bench - Light Sequential Performance
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  • sfc - Wednesday, March 25, 2015 - link

    Fool me once, shame on, shame on me. A fool me can't get fooled again.

    I *KNEW* OCZ was a garbage company after all the havoc they caused in the late 90s/early 00s with their crap memory products. It sounded alarm bells in my head that reminded me of their fake address that was literally an empty storefront.

    But I read all the press, heard how it was just the same name but a different backing company. So I bought one of their SSDs like a fool, only to send it back multiple times and everytime have it die again. I still have an 80GB intel SSD I bought several years before the OCZ that's still kicking.

    After all that, I find out the same crook selling crap memory was behind the "new" OCZ. Pulling his same parlor tricks giving review sites hand-picked models and sending bottom barrel reject flash to customers. You should just refuse to review any more of their hardware, they're crooks and their wares are trash.
    Reply
  • Jahzah_1 - Wednesday, March 25, 2015 - link

    Just picked up a Samsung 850 Evo for $204 at Microcenter (price matched to Newegg), last Saturday. Don't understand the justification by OCZ to price the 480GB version at $275. Reply
  • Jahzah_1 - Wednesday, March 25, 2015 - link

    That is $204 for the 500GB Evo. Reply
  • mapesdhs - Wednesday, March 25, 2015 - link

    As I understand the intent of this product, it's aimed at the likes of the Extreme Pro
    and 850 Pro. The Arc 100 is the mainstream competitor to the EVO, which is $196
    on newegg for the 480GB.

    Ian.
    Reply
  • Jahzah_1 - Thursday, March 26, 2015 - link

    oh, I see. What I didn't take into account was the fairly inexpensive nature of 3D-Nand production. So Samsung has an edge it seems, to set their mid-range drives at that price. Reply
  • rocketman122 - Thursday, March 26, 2015 - link

    Ive had nothing but bad experience with OCZ. I had mem go bad, rma and sold them. I had the core 64 SSD that the company knew were problematic and still didnt have integrity to not sell them. that core SSD cost me quite chunk of money and I suffered with that. I never for

    I hope they go out of business and stop selling their gear to the public. we need companies with reliable gear.
    Reply
  • ocztosh - Monday, March 30, 2015 - link

    Hello rocketman122, thank you for your comments and sorry to hear that you had issues with the Core Series. The old company no longer exists and the IP was purchased by Toshiba. As OCZ Storage Solutions - A Toshiba Group Company we have completely redone our products and processes and there has been a great focus on quality throughout the organization. Everything from the product design cycle through manufacturing has been updated. By implementing our own in-house controller and firmware technology and having access to premium Toshiba NAND we are now able to impact this better than ever. We believe we have a very competitive offering today when it comes to reliability and product quality and hope that we will have the opportunity to prove it to you in the future. Thank you again for your previous business. Reply
  • loimlo - Thursday, March 26, 2015 - link

    Good SSD review as usual. Kudos to Kristian's efforts.
    Btw, I wonder the M-I-A BX100 review. Can we expect it ?
    Reply
  • Kristian Vättö - Friday, March 27, 2015 - link

    It's coming. This month has been full of NDAs, which have postponed the BX100 review, but once I'm done with next week's NDAs the BX100 will be getting my full attention :) Reply
  • loimlo - Saturday, March 28, 2015 - link

    Thanks for clarification. Take your time to do it ~~ Reply

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