The Toshiba XG6 1TB SSD Review: Our First 96-Layer 3D NAND SSD
by Billy Tallis on September 6, 2018 8:15 AM ESTMixed Random Performance
Our test of mixed random reads and writes covers mixes varying from pure reads to pure writes at 10% increments. Each mix is tested for up to 1 minute or 32GB of data transferred. The test is conducted with a queue depth of 4, and is limited to a 64GB span of the drive. In between each mix, the drive is given idle time of up to one minute so that the overall duty cycle is 50%.
The mixed random I/O performance of the Toshiba XG6 jumps by about 47% compared to the XG5, making it competitive with most current high-end TLC drives.
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Thanks to the big performance boost at almost no cost in added power consumption, the Toshiba XG6 takes an 11% lead over the nearest competition in power efficiency on this test.
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The Toshiba XG6 is able to increase performance throughout the test as more writes are added to the workload, with much more performance growth than the XG5 showed. The performance growth falters a bit near the end of the test but the XG6 still delivers the expected performance spike with the final phase of the test as the workload shifts to pure writes.
Mixed Sequential Performance
Our test of mixed sequential reads and writes differs from the mixed random I/O test by performing 128kB sequential accesses rather than 4kB accesses at random locations, and the sequential test is conducted at queue depth 1. The range of mixes tested is the same, and the timing and limits on data transfers are also the same as above.
The mixed sequential I/O performance of the XG6 is a bit faster than the XG5, but not enough to boost it up to the top tier of drives. The relatively poor QD1 sequential performance compared to the competition is holding back the XG6 here.
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| Power Efficiency in MB/s/W | Average Power in W | ||||||||
In spite of mid-tier performance, the XG6 still manages very good power efficiency that is a bit better than the XG5 and not too far behind the WD Black. However, the XG6 will also soon be beat by numerous upcoming Phison E12 drives even if the latter are still using the older 64-layer Toshiba 3D TLC.
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Slow QD1 read speeds are the main factor keeping the XG6 from matching the overall performance scores of the top tier of drives. The XG6 also shows a bit of performance variation during the second half of the test due to garbage collection or a full SLC cache, but the impact is not severe.
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DanNeely - Friday, September 7, 2018 - link
As long as the tests are the same, you can always pull the comparisons up yourself in Bench.While I sympathize with wanting them in the article tables, 3 or 6 years of historical low/mid/high end SSDs would end up either eating a lot of the tables reducing the number of current drives listed or making them much longer, so I fully understand why very little of that data is in the main tables.
wumpus - Thursday, September 6, 2018 - link
DRAM buffer isn't mentioned but board has 4 chips on it, two are obviously flash chips, one is the Toshiba controller and one is by Nanya, a DRAM manufacturer. The kicker is that as an OEM part, the final customer has no way of telling if that chip is populated before purchase (and the lack of specs make it easier to leave it off).Hopefully if these make it to the open market we can at least tell if they have the DRAM or not. Note that some of the cheaper NVMes (think ADATA XPG 6000) seem to do fine without DRAM, but they are priced to compete with SATA, not other NVMes.
Billy Tallis - Thursday, September 6, 2018 - link
No XG6-based OEM drive is going to be DRAMless. Toshiba has the BG series for that purpose, with an entirely different controller.wumpus - Thursday, September 6, 2018 - link
Really? Then who took that photo? Is the board in the photo the board that you reviewed? That board clearly has this chip on it:http://www.nanya.com/en/Product/4228/NT6CL128M32CM...
That's a 4Gb (512MB) LPDDR3 DRAM chip. Don't tell me that the board in the photograph doesn't have DRAM. They might not ship DRAM with the OEM devices, but that doesn't mean they didn't give you a SSD with DRAM to review.
MrSpadge - Thursday, September 6, 2018 - link
He did not say"No, XG6-based OEM drive is going to be DRAMless",
just
"No XG6-based OEM drive is going to be DRAMless."
i.e. none of these drives will be DRAMless.
wumpus - Thursday, September 6, 2018 - link
My eyes are going. Should I go get a monitor with less dot pitch or get a mac where it doesn't force dot pitch to the monitor size? Decisions, decisions.Commas are just to small for modern monitors. I was planing on getting higher dot pitch, but now I'm wondering.
Valantar - Friday, September 7, 2018 - link
I doubt a different monitor would help if your eyes are inserting punctuation where there is none - missing it when it's there is another matter. Besides, the fact that the sentence with an inserted comma doesn't add up grammatically should have tipped you off.Walkeer - Thursday, September 6, 2018 - link
testing ssd performance on intel plaform is like testing race slicks tires on a child paddle car. Intel I/O performance went down by tens of percents with all the meltdown/spectre mitigations. please use AMD plaform insteadMrSpadge - Thursday, September 6, 2018 - link
Usually they keep testing environments consistent for 1-2 years exactly due to such changing software conditions. It could well be that the next test suite will feature AMD CPUs and, as always, yield results not strictly comparable to the older ones.29a - Thursday, September 6, 2018 - link
If that was the case they wouldn't use the spectre/md patches.