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I'll have to write a UCD post. For the most part, most of what I've done has been mentioned in this thread. I can tell you that I received benchmarks upwards of 350MB/s sometimes up to 400MB/s using a Samsung PM 840 PRO 256GB SSD. with a 3TB Seagate it was around 195MB/s. These are raw DD benchmarks of reading the drive directly with no filesystem I/O. With filesystem I/O this changes because of journaling and other housekeeping. Also the HPN54L has PCIe gen 2 ports. I found the correct speed spec for PCIe : Per lane (each direction): v1.x: 250 MB/s (2.5 GT/s) v2.x: 500 MB/s (5 GT/s) v3.0: 985 MB/s (8 GT/s) v4.0: 1969 MB/s (16 GT/s) So, a 16-lane slot (each direction): v1.x: 4 GB/s (40 GT/s) v2.x: 8 GB/s (80 GT/s) v3.0: 15.75 GB/s (128 GT/s) v4.0: 31.51 GB/s (256 GT/s) you are right, for PCIe v2, it is 500MB/s, and if it is 300-400MB/s is consider very fast. .

WeeboTech, Would you mind give me details on how you setup the 2 N54L, hardware configuration and software configuration. as a reference on maximizing the benefit of ESXi and unRaid on the little boxes. BTW, if the startech card is only PCIe x1, it should have its own limitations in data transfer speed although the chipset can support 6gbps ...... PCIe x1 - maxi data transfer speed is cannot exceed 250MBs.

I have installed unRAID 5.Xrc under ESX 5.1 on a microserver with 16GB of ram. I allocated 1GB to unRAID. Using internal SATA, External SATA, ASmedia and SIL3134, SIL3132 cards I get 'raw' read rates from 95MB/s up to 180MB/s on the ASmedia 6GB/s SATA card. These are raw DD reads of the hard drive itself, bypassing any form of network or filesystem reads. When writing to a drive without parity, the speeds varied anywhere from 90MB/s up to 195MB/s depending on how much data I was writing and whatever filesystem allocation there was. i.e. journaling absorbs some of the raw speed for writing. I used port multipliers also and they were in the 100-120MB/s range for a single drive on the Silicon Image chipset and up to 190MB/s on the ASmedia SATA III card. Tests were done using the Seagte 3TB 7200 RPM drive. I used vmkfstools with the -z and -a pvscsi option to RDM the entire disk. My tests without RDM proved to be quite slow and almost pointless to have resierfs on top of a virtual .vmdk container file on top of a VMFS data store. Even with fast RAID0 using 2 3TB drives, it was painfully slow and lengthy just to format. 1. Format the data store (fast). 2. Create the .vmdk (about hour and half). 3. Format the reiserfs filesystem (40 minutes or so). RDM of the disk was almost as fast as native bare metal unraid. Very close in speed. As far as transfer over the network. I did not test it. I knew if unRAID could read/write to the disk under ESX as fast, or nearly as fast, as bare metal, the rest would work at acceptable levels. What network adapter did you choose? E1000 or VMXNET? What SCSI adapter did you use for the RDM disk (if you configured it that way). I found the LSI SAS adapter to be fast, but it bottle necked at around 120 MB/s. I immediately reconfigured with the PVSCSI adapter and the speed went up to 180MB/s. as a test do this to see your raw hard drive read capability. dd if=/dev/sd? of=/dev/null bs=4096 count=1024000 Where ? is the device's last character. This will read 4GB raw from the hard drive. It will show you the maximum speed you could possibly get from the hard drive for sequential data on the outer tracks. There are all sorts of file system references that occur, so file reads on a formatted file system will be slower. you can do the same to write a file and read it if the hard drive is mounted echo 3 > /proc/sys/vm/drop_caches # drop pagecache, dentries and inodes dd if=/dev/zero of=/mnt/disk1/test.dd bs=4096 count=1024000 echo 3 > /proc/sys/vm/drop_caches # drop pagecache, dentries and inodes dd if=/mnt/disk1/test.dd of=/dev/null bs=4096 count=1024000 Hi, When u did these tests, is it With modified bios, Esxi Unraid on top , with rdm PCIe raid card, with esata ports connected to external enclosure ? Btw, how do you use the 4 bay come with the box ?