![]() ![]() There were just so many variables I wanted to make sure I wasn't missing something. I am running the latest firmware and drivers for the LSI MegaRAID 9271-8i A 4k random write with a depth queue of 1 offers double the throughput and IOPS. Pay close attention to the random writes. Reversing these settings makes no difference. ![]() I have a single disk in RAID0 set to "write-through" and "never-read-head" so in theory the cache on the controller isn't being used and there should be little to no bottleneck. The RAID card may be a potential bottleneck.I'm skeptical of this though because writing 0s to the entire disk and testing it through the RAID controller made no difference. TRIM does not work on any SSD connected to an LSI card but does through the motherboard.I wonder if this could be causing the latency? This means all LSI cards will disable it by default (at least this is what I have read, I think this is referred to as the disk-cache-policy). 850 Pros are Consumer SSDs do not have capacitor for the on-board DRAM.I would really like to understand why this his happening. I am seeing a 25% increase in IOPs when performing a 4k 100% write test with a single SSD hooked directly to the motherboard vs the RAID controller. Another question in my ongoing RAID project with Samsung 850 Pro SSDs ![]()
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