Dell D16U Einrichtung und Spezifikationen - Seite 18
Blättern Sie online oder laden Sie pdf Einrichtung und Spezifikationen für Desktop Dell D16U herunter. Dell D16U 23 Seiten. Accessories
Auch für Dell D16U: Installationshandbuch (24 seiten)
Seite drucken
NOTE:
RAID is not supported on Intel Optane configurations.
RAID 0 (Striped, Performance) volumes benefit from higher performance when drives are matched because the data is split
across multiple drives: any IO operations with block sizes larger than the stripe size will split the IO and become constrained by
the slowest of the drives. For RAID 0 IO operations where block sizes are smaller than the stripe size, whichever drive the IO
operation targets will determine the performance, which increases variability and results in inconsistent latencies. This variability
is particularly pronounced for write operations and it can be problematic for applications that are latency sensitive. One such
example of this is any application that performs thousands of random writes per second in very small block sizes.
RAID 1 (Mirrored, Data Protection) volumes benefit from higher performance when drives are matched because the data
is mirrored across multiple drives: all IO operations must be performed identically to both drives, thus variations in drive
performance when the models are different, results in the IO operations completing only as fast as the slowest drive. While
this does not suffer the variable latency issue in small random IO operations as with RAID 0 across heterogeneous drives, the
impact is nonetheless large because the higher performing drive becomes limited in all IO types. One of the worst examples of
constrained performance here is when using unbuffered IO. To ensure writes are fully committed to non-volatile regions of the
RAID volume, unbuffered IO bypasses cache (for example by using the Force Unit Access bit in the NVMe protocol) and the IO
operation will not complete until all the drives in the RAID volume have completed the request to commit the data. This kind of
IO operation completely negates any advantage of a higher performing drive in the volume.
Care must be taken to match not only the drive vendor, capacity, and class, but also the specific model. Drives from the same
vendor, with the same capacity, and even within the same class, can have very different performance characteristics for certain
types of IO operations. Thus, matching by model ensures that the RAID volumes is comprised of an homogeneous array of drives
that will deliver all the benefits of a RAID volume without incurring the additional penalties when one or more drives in the
volume are lower performing.
Precision 3260 Compact supports RAID with more than one hard drive configuration.
Power adapter
The following table lists the power adapter specifications of your Precision 3260 Compact.
Table 14. Power adapter specifications
Description
Type
Connector dimensions:
External diameter
Internal diameter
Power-adapter dimensions:
Height
Width
Depth
Input voltage
Input frequency
Input current (maximum)
Output current (continuous)
Rated output voltage
Temperature range:
Operating
18
Specifications of Precision 3260 Compact
Option one
180 W E4
7.40 mm (0.29 in.)
5.10 mm (0.20 in.)
30.00 mm (1.18 in.)
76.20 mm (3.00 in.)
155 mm (6.10 in.)
100 VAC–240 VAC
50 Hz–60 Hz
2.34 A
9.23 A
19.50 VDC
0°C to 40°C (32°F to 104°F)
Option two
240 W E4
7.40 mm (0.29 in.)
5.10 mm (0.20 in.)
25.40 mm (1.00 in.)
100.00 mm (3.94 in.)
200 mm (7.87 in.)
100 VAC–240 VAC
50 Hz–60 Hz
3.5 A
12.31 A
19.50 VDC
0°C to 40°C (32°F to 104°F)