While synthetic workloads do a great job of testing the underlying technology and reporting easy to understand results, they aren’t always indicative of how the drive will be used by the end user. Workloads that simulate enterprise environments try to bridge that gap without being overly complex.
The database profile is 8K transfers, and 67% percent of operations are reads.
At low queue depths, the ALLONE does a terrific job running our database profile. Unfortunately, the superior high queue depth read performance allows the competition to pull ahead at the end.
The fileserver profile is based on an 80% read/20% write mix. Its made up of blocksizes from 512 to 64K, each making up a different percentage of the access pattern. The pattern is: 512 bytes=10%, 1k=5%,2k=5%, 4k=60%, 8k=2%, 16k=4%, 32k=4%, 64k=10%.
Not much changed in our fileserver testing. The ALLONE came out strong in the low queue depths, but didn’t have the read performance to maintain it.
The webserver profile is similar to the fileserver profile, but has some additional 128K and 512K accesses thrown in for good measure. Additionally, the profile is 100% read.
This is probably the worse case scenario for the ALLONE, lots of random and sequential reads. It was able to keep a lead for the first few queue depths, but eventually got left in the dust.
REPORT ANALYSIS AND FINAL THOUGHTS
After all of the testing, we came away with a couple conclusions that may seem obvious, but we had to do the testing to prove it. The first is that the ALLONE Cloud Disk Drive 101 is not an SSD. Other than the fact that you can write to and read from it, it shares very few similarities. In some ways, that’s a good things.
We love the fact that this device has unlimited write endurance. As a caching solution, the ALLONE should be bulletproof against any kind of workload. But, that excitement is tempered by the use of more commercial components.
We were impressed by the symmetric performance and how previous operation had zero affect on the current workload. It seriously drives enterprise SSD reviewers up a wall trying to get SSDs to enter and stay in steady-state. With the ALLONE, that isn’t a factor in any way.
The real issue is that the Cloud Disk Drive 101 is a niche product. At 32GB, it is limited in size, which will limit its applications. It performs well in certain areas, but gets thrashed in other areas by PCIe SSDs. ALLONE has put all of its efforts in touting the drive’s 512B performance, but we aren’t sure how many applications will take full advantage of that.
ALLONE makes it very clear that they are going up against Fusion-io. When they aren’t calling them out by name in their comparison documents, they are referring to them as Tier-F. This also helps explain the pricing. At $15K, the price is going to be a hard pill to swallow for most, but when compared to what Fusion-io charges, that isn’t exactly out of the question. We have to believe that this is a product that was better suited for 3 years ago. With NVMe hitting servers as we speak, the gap in performance is closing fast. In fact, the Intel SSD DC P3700, especially the 1.6TB model, would have beat the ALLONE in almost every way at a third of the price.
After talking with ALLONE, we got a better understanding to where this product belongs. They want to augment their customer’s tiered storage solution. They want their product to get in between typical PCIe SSDs and DRAM. They want to accelerate small block transfers using as little power as possible. We can understand that. Their challenge may be convincing customers that their storage rack needs another level of storage.
It’s not all doom and gloom. If ALLONE can make a few evolutionary changes, such as a PCIe x4 Gen3 interface, more DIMM slots and DDR4 support, that can move that curve back in their favor. As it stands, this product is for people that need unlimited write endurance for 512B workloads and are willing to pay for it.