BIOSTAR is a new player in the SSD market, but they have decades of experiences manufacturing PC components, especially motherboards. For their M700 SSD, BIOSTAR has chosen to pair Intel 64-layer 3D TLC flash with a SM2263XT controller from Silicon Motion. A DRAM chip is not installed—definitely for cost optimization. Thanks to a PCI-Express 3.0 x4 interface, the drive can impress with outstanding read speeds of 2.8 GB/s and 1.6 GB/s writes. At $50, the M700 is the most affordable NVMe SSD ever released, cheaper than even most 2.5" SATA drives on the market.
DRAM on an SSD is used as fast temporary storage for the drive's internal mapping tables, which translate between physical disk addresses (the OS sees) and the actual location of where the data is stored in the flash chips: "which chip, at which location". Using DRAM has a speed advantage as it operates much faster than flash, but it's a cost/performance trade-off. A 1 TB SSD typically uses 1 GB of DRAM, which costs a few dollars. If you can save that, you'll be able to position your drive more aggressively, leading to more sales, or you'll enjoy higher margins.
For nearly all consumer workloads, random write performance over a large area doesn't really matter. Consumer workloads are very read-heavy anyway, and if writes happen, they are localized over a relatively small area, which is exactly why DRAM-less SSDs were invented.
Averaged over all our benchmarks, we see the BIOSTAR M700 neck-to-neck with the ADATA SX6000 Pro (DRAM-less, Phison), Intel 760p (DRAM, SM2262), and Crucial P1 (DRAM, QLC, SM2263). The big difference is that the M700 is MUCH more affordable than these options, in some cases half(!) the price. Of course, topnotch NVMe drives like the Samsung 970 Pro and ADATA SX8200 Pro are faster, but the differences are much smaller than expected, especially considering the M700 is a highly affordable DRAM-less drive. Compared to SATA SSDs, the M700 is the clear winner, having an edge in pretty much all of our benchmarks, sometimes a quite significant one (when it can play out its transfer rate advantage).
With 62 GB, the write cache of the M700 is large, larger than on most other drives on the market, which will come in very handy with soaking up bursts of write activity. While other drives slow down after only a few GB written, the M700 handled 62 GB in that same test, which has obvious advantages. Once the write cache is exhausted though, the drive's write speed drops down to around 250 MB/s, which is a huge drop and slower than even some SATA SSDs. However, you have to consider pricing again and that the drive is marketed towards average consumers who'll never write that much data in one go anyway.
Even though the M700 lacks a dedicated heatsink, it did well in our thermal testing. While the drive is not completely free of throttling, there's plenty of headroom for all reasonable scenarios. In our testing, we were able to write 1.25 GB/s non-stop without any thermal throttling for extended periods of time, which is actually better than most other M.2 drives we tested. You also have to look at the SATA comparison. Even when running in its thermal throttle state, write speeds are still much higher than on any 2.5" drive, which is bottlenecked by the SATA interface all the time.
The real killer argument for the M700 is its pricing. With just $50 for the tested 512 GB variant, the drive shatters the 10 cents per GB barrier and delivers very respectable performance at the same time. If you are looking for an affordable M.2 NVMe SSD then this is the drive you should go for. If your motherboard supports M.2 NVMe and you have a slot available, there's very little reason to pick a 2.5" SATA drive instead. Performance definitely isn't one of those reasons, neither is cost per GB. I do wish BIOSTAR would be a bit more forthcoming with their TBW endurance rating as it's simply stated as "3 years warranty", which might turn away some potential customers. Also, it would be great to see a 2 TB version, and I'm sure a lot of people would be willing to spend a few more bucks to get a version with DRAM cache.