Seagate 15K.5 Economies of Capacity and Speed: Choosing the most cost-effectiv
Seagate 15K.5 - Cheetah - Hard Drive Manual
UPC - 200001261244
View all Seagate 15K.5 manuals
Add to My Manuals
Save this manual to your list of manuals |
Seagate 15K.5 manual content summary:
- Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 1
acquisition price/GB) or 300GB 10K (lowest price per GB). Were cost/capacity truly the dominant purchase criterion used by IT departments, they would instead be buying 300GB 10K drives (see Figure 1). 350 Capacity 300 300 of 10K 250 Offered 200 Gbytes 150 146 100 50 36 73 0 Q1 - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 2
ms) 10K 146 GB 14 725 22.1 15K 146 GB 14 955 16.7 32% Faster 24% Faster All values are calculated based on previous generation drive test results from IBM xSeries 335 with EXP 400:8KB, 2/3 random read, 1/3 random write, queue depth 16. Figure 3. 10K vs. 15K comparison 15K drives are able - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 3
.3 19.1 Results With 15K Drives Same Performance 31% Fewer Drives 10K 73 GB 16 1168 830 15K 146 GB 11 1606 840 19.3 Same Performance 37% More Capacity 19.1 31% Fewer Drives All values are calculated based on previous generation drive test results. Figure 5. 10K vs. 15K comparison IT - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 4
buy 10K 73GB drives, but elect to purchase 10K 146GB drives and short-stroke them to increase their performance. Nevertheless, for a given capacity and performance level (even when 10K drives are short-stroked), fewer 15K drives than 10K drives are required. Drive Comparison 10K 300 GB 15K 146 GB - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 5
decision support. 10K-RPM drives are better suited for applications where data is infrequently accessed. Storage Performance Council testing, which includes e-mail in its workloads, verifies the cost efficiency of 15K-RPM disc drives. All top SPC price/performance leaders elected to use 15K drives - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 6
disc to make one complete revolution is 4.0 msec for a 15K drive (vs. 6.0 msec for a 10K drive). When a seeking head reaches the target track, the full revolution (4.0 msec) before reading the data. Thus latency on a 15K-RPM drive averages out to 2.0 msec. Data Transfer Time: For the majority of - Seagate 15K.5 | Economies of Capacity and Speed: Choosing the most cost-effectiv - Page 7
. Such underutilized media results in a very high cost-perusable-GB and cost-per-IOPS solution for the end user. 15K-RPM disc drives lower access time without forcing users to sacrifice the capacity on the disc. Thus fewer 15K-RPM disc drives of a given capacity are needed to meet the performance
Economies of Capacity and Speed:
Choosing the most cost-effective disc drive
size and RPM to meet IT requirements
Introduction
IT departments are under growing pressure to find the most cost-effective means to meet their escalating data storage
requirements, including disc drive capacity and performance. Today’s storage systems must hold ever-increasing amounts of data,
achieve input/output (I/O) performance goals, meet client response-time expectations and minimize physical space (U or ft3)
requirements. Furthermore, IT professionals must ensure their storage systems are reliable-maximizing system availability while
minimizing drive failures, the number of RAID rebuilds and RAID rebuild time. All of these factors can come into play when
determining the optimal capacity and speed of a system’s disc drives.
In this paper we will discuss a variety of factors that impact the choice of disc drive capacity and speed for systems that offer a
choice between 3.5-inch 10K-RPM drives and 3.5-inch 15K-RPM drives. Let us start by looking at the current trend in drive
purchase decisions.
While IT departments often speak of buying drives on the basis of cost/capacity (price per GB), the majority of
drives they will actually purchase are 36GB 10K (lowest price box cost), as opposed to 146GB 15K (highest initial acquisition
price/GB) or 300GB 10K (lowest price per GB). Were cost/capacity truly the dominant purchase criterion used by IT departments,
they would instead be buying 300GB 10K drives (see Figure 1).
Why have IT departments preferred 10K 36GB drives? The history of disc drives and other system component offerings will shed
some light on this.
TP-525 • From: Seagate Global Product Marketing • May 2004
Technology Paper
Figure 1. IT departments are not buying the lowest cost/GB drives.
350
300
250
200
150
100
50
0
Gbytes
Q1
Q2
Q3
Q4 Q1
Q2
Q3
Q4 Q1
Q2
Q3
Q4 Q1
Q2
Q3
Q4 Q1
Q2
2001
2002
2003
Calendar Year
2004
2005
300
146
73
36
Capacity
of 10K
Offered
Average
Capacity
Purchased