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In short: if using a low-end RAID card (without cache), do yourself a favor and switch to software RAID. If using a mid-to-high-end card (with BBU or NVRAM), then hardware is often (but not always! see below) a good choice. Long answer: when computing power was limited, hardware RAID cards had the significantly advantage to offload parity/syndrome ...


4

There are a few issues here. You don't have any controller write cache or a battery-backed or flash-capacitor. The HP Smart Array P410 controller is limited in IOPS capacity. It's not a good match for SSDs. Using SATA drives on a Smart Array P410 causes the interface speed to downshift to 3.0Gbps instead of 6.0Gbps. Please try with RAID 1+0. RAID5 is not ...


3

You'll want a battery or flash-backed cache solution for any hardware controller you purchase. Most regret not doing so. But to answer your question, most controllers have configurable cache ratios... so 100% read cache and 0 % write cache negates the need for BBU protection. Your write performance will just suck. I can't address your software RAID ...


3

The RAID-controller you have your eye one is a cheap one and is basically a fakeraid. It even depends on your mainboard to provide some functions like memory and not a lot of mainboards have support for it which results in that you can't load the driver. About HW vs SW-RAID itself. I'm not using HW-RAID anymore unless it is a box with an EMC logo on it for ...


2

MLC SSD really need a fast private DRAM cache for delivering high IOPS values. While your controller has its own cache and it is enabled, your disk's private DRAM cache is disabled. This is a safety measure, as enabling that unprotected (from power losses) cache can put your data at risk. Sometime it is safe to reenable it (eg: your disks has power loss ...


2

Most of the writers here are just ignorant of "write hole". This is the basis which allows for crying out for battey backup units of hardware RAIDs vs. absense of a such for software RAIDs. Well, for e. g., Linux software RAID implementation either supports bitmaps of write operations or does full "parity" re-calculation in case of not-clean shutdown. ZFS ...


2

The cache on the card is getting in the way. The raid card cache is designed to enhance the performance of spinning drives. The best option on most ssd array is direct io and write through. You can test the different performance using hdtune or various other tools. You can leave the drive cache enabled.



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