Although Native Command Queuing is most definitely an elegant and intelligent way to minimize the impact of a hard drive's mechanical latency, our test results show that better performance certainly isn't guaranteed with the Barracuda 7200.7 NCQ and Promise's FastTrak TX4200. The best applications for NCQ are undoubtedly the kinds of multi-user environments that IOMeter simulates. With an increasing number of concurrent I/O requests to read or write data from different areas of a disk, command queuing's optimized request rescheduling really shines. NCQ also scales better with lower I/O loads than Western Digital's Tagged Command Queuing, whose CPU utilization is also much, much higher.
Unfortunately, IOMeter is about the only place where NCQ seems to help the Barracuda 7200.7. In fact, command queuing actually hurts the drive's performance in typical single-user applications, sometimes by a significant margin. Trying to pin down why NCQ slows the Barracuda down in some tests is more difficult, although the Raptor with TCQ is also plagued by poor single-user performance, so overhead associated with the Promise FastTrak TX 4200 controller may be the culprit.
At the end of the day, Native Command Queuing is undoubtedly The Right Thing to do. It's clearly a winner for servers that face multi-user loads, but the implementations we tested need to mature before they become attractive alternatives for single-user desktops. Given that it's entrenched in the Serial ATA II spec, we'll be seeing a lot more of Native Command Queuing moving forward. I can only hope that the next generation of drives and SATA controllers will, across the board, at least be no slower with NCQ than they are without.
54 comments — Last by indeego at 12:38 AM on 05/06/05
|Some 840 EVOs still vulnerable to read speed slowdownsPatched drives exhibit problems with old data||4|
|Samsung's Portable SSD T1 reviewedA pocketable 850 EVO||32|
|Samsung's 850 EVO solid-state drive reviewed3D V-NAND's destiny||55|
|The SSD Endurance Experiment: Two freaking petabytesThe survivors soldier on to another really big number||60|
|Corsair's Neutron Series XT solid-state drive reviewedMy SSD controller has more cores than yours||24|
|Samsung's 840 EVO update fixes slow reads with old dataAn early look at the EVO's Performance Restoration tool||28|
|Micron's M600 solid-state drive reviewedA truly dynamic SLC/MLC hybrid||24|
|The SSD Endurance Experiment: Only two remain after 1.5PBAnother one bites the dust||76|
|Some 840 EVOs still vulnerable to read speed slowdowns||4|
|Nvidia: the GeForce GTX 970 works exactly as intended||47|
|Report: 4GB of RAM coming to GTX 960 in March||68|
|Early deal of the week: A 27" G-Sync monitor for $480||24|
|Gearbox's Homeworld remake due February 25||34|
|Nvidia admits, explains GeForce GTX 970 memory allocation issue||238|
|Here's my guest appearance on tonight's Alt+Tab Show||12|
|Watch John Romero talk about Doom level design||46|
|HA. AMD in the red and nVidia in the green. Thats funny cause you know... *cough* oh forget it.||+82|