HP X Class 500/550MHz hp visualize workstation - SDRAM Advantages with the HP - Page 9

Other Applications, Concluding Thoughts

Get HP X Class 500/550MHz PDF manuals and user guides View all HP X Class 500/550MHz manuals
Add to My Manuals
Save this manual to your list of manuals

Page 9 highlights

Other Applications The example above was chosen for this analysis because it illustrates how latency can have a large effect on application performance even if the misses are in bursts. Many technical applications have lower miss rates than this example, but the average burst size is also lower so the sensitivity to latency is still high. Some applications will benefit more from a high performance SDRAM memory architecture and some less. Applications that have a higher miss rate or if the misses cannot be burst will benefit more. In one case, the same application and workload was compared on the two memory systems with two different graphics cards. With one of the graphics cards the SDRAM system was 10 percent faster. With the other graphics card the SDRAM system was 14 percent faster. This can be explained by the differences in the graphics card drivers. The first driver had a lower cache miss rate or it did a better job of pre-fetching the data. Both of these would result in the CPU spending less time waiting for data to return from main memory and more time doing useful work. A graphics driver is just a specialized application, and each one will have unique memory access characteristics like any other application. Concluding Thoughts There are many ways to access memory. This paper explores just one of those methods, but it is a critical method-one that has a direct effect on application performance. None of this should suggest that RDRAM technology isn't the right choice for some implementations. In reality, it has some distinct advantages with smaller RAM configurations. But these advantages are diminished when RDRAM is used in larger workstations with many memory chips. As noted above, the bandwidth advantages of RDRAM only matter to a certain point on memory-hungry technical applications. Beyond that, the issue becomes latency. And SDRAM technology has clear advantages when it comes to delivering lower latency. Ultimately, this lower latency leads to higher application performance. 1/5/2000 HP VISUALIZE WORKSTATIONS 8

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
The example above was chosen for this analysis because it illustrates how latency
can have a large effect on application performance even if the misses are in bursts.
Many technical applications have lower miss rates than this example, but the average
burst size is also lower so the sensitivity to latency is still high.
Some applications
will benefit more from a high performance SDRAM memory architecture and some
less.
Applications that have a higher miss rate or if the misses cannot be burst will
benefit more.
In one case, the same application and workload was compared on the two memory
systems with two different graphics cards.
With one of the graphics cards the
SDRAM system was 10 percent faster.
With the other graphics card the SDRAM
system was 14 percent faster.
This can be explained by the differences in the graphics card drivers.
The first driver
had a lower cache miss rate or it did a better job of pre-fetching the data.
Both of
these would result in the CPU spending less time waiting for data to return from main
memory and more time doing useful work.
A graphics driver is just a specialized
application, and each one will have unique memory access characteristics like any
other application.
There are many ways to access memory.
This paper explores just one of those
methods, but it is a critical method-one that has a direct effect on application
performance.
None of this should suggest that RDRAM technology isn’t the right choice for some
implementations.
In reality, it has some distinct advantages with smaller RAM
configurations. But these advantages are diminished when RDRAM is used in larger
workstations with many memory chips.
As noted above, the bandwidth advantages of RDRAM only matter to a certain point
on memory-hungry technical applications. Beyond that, the issue becomes latency.
And SDRAM technology has clear advantages when it comes to delivering lower
latency.
Ultimately, this lower latency leads to higher application performance.
HP VISUALIZE WORKSTATIONS
1/5/2000
8
Other Applications
Concluding Thoughts