Performance Focus – 860 PRO 512GB
A quick note on these results: I’ve been analyzing the effects of how full an SSD is on its performance. I’ve found that most SSDs perform greater when empty (FOB) as they do when half or nearly filled to capacity. Most people actually put stuff on their SSD. To properly capture performance at various levels of fill, the entire suite is run multiple times and at varying levels of drive fill. This is done in a way to emulate the actual use of the SSD over time. Random and sequential performance is rechecked in the same areas as data is added. Those checks are made on the same files and areas checked throughout the test. Once all of this data is obtained, we again apply the weighting method mentioned in the intro in order to balance the results towards the more realistic levels of fill. The below results all use this method.
Sequential performance looks good. Near full speed at QD=1.
Now for random access. The blue and red lines are read and write, and I've thrown in a 70% R/W mix as an additional data point. SSDs typically have a hard time with mixed workloads, so the closer that 70% plot is to the read plot, the better.
Something our readers might not be used to is the noticeably higher write performance at these lower queue depths. To better grasp the cause, think about what must happen while these transfers are taking place, and what constitutes a ‘complete IO’ from the perspective of the host system.
- Writes: Host sends data to SSD. SSD receives data and acknowledges the IO. SSD then passes that data onto the flash for writing. All necessary metadata / FTL table updates take place.
- Reads: Host requests data from SSD. SSD controller looks up data location in FTL, addresses and reads data from the appropriate flash dies, and finally replies to the host with the data, completing the IO.
The fundamental difference there is when the IO is considered complete. While ‘max’ values for random reads are typically higher than for random writes (due to limits in flash write speeds), lower QD writes can generally be serviced faster, resulting in higher IOPS. Random writes can also ‘ramp up’ faster since writes don’t need a high queue to achieve the parallelism which benefits and results in high QD high IOPS reads.
Our new results are derived from a very large dataset. I'm including the raw (% fill weighted) data set below for those who have specific needs and want to find their specific use case on the plot.
For the power users out there, here's the full read/write burst sweep at all queue depths:
Write Cache Testing
Being a PRO series SSD, the 512GB unit contains only MLC flash and no SLC cache.
I wonder how much cost is
I wonder how much cost is saves by moving to more dense nand and a smaller pcb footprint? Seeing the performance, it looks to me this was more of a shrink than a improvement.
Agreed. It’s as if they were
Agreed. It's as if they were trying too hard to make the SSD as economical as possible to produce, causing it to fall short in some areas.
It is a SATA SSD, they can’t
It is a SATA SSD, they can’t improve the performance much until the SATA bottleneck is lifted on the host side. Perhaps SATA IV is in order but I believe that will never happen. The 850 series already maxed out the SATA bus, so not exactly sure what performance improvements you would like to magically see Samsung improve upon. They already implemented improvements via M.2 PCIe ssd’s. If you want faster than SATA, you have to move on from SATA. Simple as that.
I agree: it’s as if the
I agree: it’s as if the storage “oligopoly” has conspired
to maintain an artificially low ceiling on 2.5″ SSD speeds.
Several years ago, we proposed a “SATA-IV” standard that
upped the transmission clock to 8G (like PCIe 3.0 lanes)
and changed the 8b/10b legacy frame to the 128b/130b
“jumbo frame” that is already standard in PCIe 3.0:
8 GHz / 8.125 bits per byte = 984.6 MB/second
i.e. exact same throughput as a single PCIe 3.0 lane.
Admittedly, that is not a massive increase; nevertheless,
one could easily approximate one NVMe port with
four such SSDs in a RAID-0 array, and the wiring
topologies for such a RAID array are ubiquitous.
FYI: here’s a copy of our SATA-IV Proposal to the
Storage Developer Conference in 2012:
And, now that the PCIe 4.0
And, now that the PCIe 4.0 standard has been released,
a future SATA-IV standard should support a 16 GHz clock:
16G / 8.125 bits per byte = 1,969.2 MB/second.
Thus, 4 such SSDs in a RAID-0 array should max out
at ~ 7.87 GB/second (no overhead). Yes, the SATA
protocol does have more inherent overhead, but
its installed base is already HUGE. Increasing the
clock rate and upgrading to jumbo frames should be
a piece o’ cake for storage industry manufacturers.
And, RAID controllers could still support PCIe 3.0
edge connectors, while increasing the clock speed
on their SATA connectors to 16 GHz. Maybe Allyn
could offer this suggestion to Areca?
I doubt there will be another
I doubt there will be another SATA spec for SSD drives. SSD drives will move too PCIe and SATA will be for slower bulk storage.
Allyn, I think the last trim
Allyn, I think the last trim chart may have the wrong x-label, not sure, I got confused there.
You are correct! Thanks for
You are correct! Thanks for the catch. It is now fixed.
Hopefully the price of the
Hopefully the price of the 850’s will go down rather than be discontinued.
Allyn, pop quiz of the day.
Allyn, pop quiz of the day.
I have 3 256gb 850 pros in RAID 1 on my boot drive (I have no sensitive data on the raid). I have all my programs/games on this “drive”. I am approaching 200gb of free space left. As you know with todays games that could be 4 new AAA titles. I have toyed with the idea of getting a single 500gb drive windows and all apps, leaving my 7xx gb raid for Steam only. Is there any benefit to doing that with one of these drives or should I just snatch up another 256gb 850 pro and increase my raid?
***I am on Z97 so an NVME boot drive isn’t possible.
RAID 1 with three drives?
RAID 1 with three drives?
Yea… I mean raid 0. Got
Yea… I mean raid 0. Got ahead of my self last night.
So long as you are good at
So long as you are good at backing up, I'd just add another 256 to the RAID-0. If your stripe size is lower, you will see a nice boost to QD1 sequentials that are larger than the stripe size (since those transfers are split across multiple drives). You're good for up to 6 SSDs in RAID on that board. While you'll hit the DMI throughput limit at ~4 SATA devices, there are still advantages to splitting your IOs across additional SSDs – even when they are bottlenecked.
I appreciate it. It all
I appreciate it. It all started when I found a smoking deal years ago on two 256gb drives, and has grown from there. I guess another 256gb 850 pro is on the horizon. The more the merrier right!?
I have a FreeNAS for redundancy and a WD Blue 2tb drive in my system as well for the important stuff. I am pretty sure my ISP hates when I re-install windows yearly and re-download my whole steam library though. 😀
You have multiple drives and
You have multiple drives and you redownload your Steam library upon Windows installation? That’s just irresponsible.
On page “https://www.pcper.com/reviews/Storage/Samsung-860-EVO-and-PRO-SATA-SSD-Review-512GB-1TB-and-4TB-Tested/Performance-Focus-0” at the end of the page you guys wrote “Being a PRO series SSD, the 2TB unit contains only MLC flash and no SLC cache.”.
The one being tested on that page is the 4TB version, there is no 2TB version being tested/shown.
So there will be 4TB M.2
So there will be 4TB M.2 variants? How long until we see a 4TB PCI-e M.2 from Samsung?
It’s down to PCB space. Not
It’s down to PCB space. Not enough room on M.2. Less room on mSATA.
I was wondering, with older
I was wondering, with older platform such as dual Xeon socket 2011 (v1) if there would be M.2 versions of these, would they function via an adapter?
I guess it would also be a general question on older platforms with NVME SSD or even Optain functioning or should I consider upgrade time to Threadripper/Ryzen?
Granted M.2 versions of these
Granted M.2 versions of these drives are not NVME, but a chance to remove cables would be a nice positive. Hence question stands for PCIE to M.2 adapters on older platforms for SATA/NVME/Optain
You’d have to use an M.2 to
You’d have to use an M.2 to SATA (not PCIe) adapter card.
The link at your article’s
The link at your article’s outset concerning the 850 line’s “silent migration to 64-layer V-NAND” actually links to your piece detailing the 850 EVO’s transition from 32- to 48-layer NAND. If a story exists about the switch to 64-layer NAND, I must have missed it.
In a similar vein, do you know if anyone has done testing to compare the 48-layer MLC/TLC versions of the 850 series drives to their 64-layer replacements?
It would be interesting to find out if the mixed workload performance and TRIM issues exhibited by the newly released 860 series were also present on the third revision of the 850 series, possibly indicating a limitation of the denser NAND rather than a bug in the new controller or firmware.
Hey, just to make sure: you
Hey, just to make sure: you did all the benchmarks in an identical environment and there was no possible microcode/Windows update for Meltdown/Spectre in between the benchmarks for the old and new SSDs, right?
860 pro cant support
860 pro cant support Raid ability?????????
It’s been 8 months since the
It’s been 8 months since the review, do you know if the TRIM issue has been fixed?
I’m deciding between the 850 or 860 currently.
Allyn have they fixed the
Allyn have they fixed the TRIM issue?