Also, is there a Intel SpeedStep like technology from the AMD stable ? On Intel P4 (Centrino) laptop, the default power-saving settings impacted the speed quite a bit, for example when I was on batteries. On 5/21/07, Phil Meyer <pmeyer@xxxxxxxxxxxxxxxx> wrote:
Srikanth Konjarla wrote: > Yes. I see degraded performance on the laptop and i totally understand > that would cause latency in any heavily disk bound applications. > However, i am not sure how it will affect the loading of application(s) > and desktop navigation in general. > > Srikanth > > Oliver Schulze L. wrote: > >> Maybe the problem is the hard disk performance, do a quick check with: >> hdparm -t /dev/sda >> >> twice(because of caching) in each PC anc compare >> >> HTH >> Oliver >> >> > > Several things to consider in basic architectural differences. 1. Your AMD laptop has a slower disk drive. 2. Your AMD laptop probably has slower memory timings. 3. Your AMD laptop may have less memory. 4. Your Laptop probably has a slower video card in it. There are other issues as well, but lets just examine the impact of these things in general desktop usage. Slower disk: This will impact application startup because reads are slower. To demonstrate this effect, time the startup of Firefox just after a reboot. Then close Firefox and time the startup of Firefox again. Do it a third time just for grins. You will see a marked decrease in the startup time of Firefox the second and third time compared to the first. Why? File caching by the operating system. The first was from disk, the second and third are from cache. repeat the timings on the desktop, and pay particular attention to the first timings as related to disk timings, and the second and third timings in relation to memory performance. Slow disk reads will also impact any application that forces paging activity. Slower memory timings: Memory timing is critical for application performance, but most desktop applications sit and wait for user interaction. Memory timings will impact application load times, compiler times, gaming performance, and many other specialized applications. A 3D desktop like Beryl will 'feel' faster on a system with great memory timings and a great video card. The amount of memory installed can also make a difference. All modern UNIX/Linux kernels will use all available memory. The bulk of memory not tied to applications is used for caches of various sorts. As demonstrated with the Firefox startup times, disk cache does impact desktop performance. Other types of caching also impact general performance. UNIX/Linux loves memory. The more the better. In general, you will see a performance difference on an otherwise identical system between 512MB RAM and 2GB RAM installed. This assumes an active desktop user, of course. Video Card Differences: This can be the most critical difference in desktop performance, even in 2D, which most desktops are rendered. Driver differences are always suspect. Fonts and display resolutions can impact performance, and plain old 'look bad'. Using a font server is mpre efficient than reading fonts from disk each time. Using fonts 'as is' instead of 'rendering' fonts takes mush less CPU. Is the laptop display resolution set to recommended (actual) ? All of these things can tax a video card even in 2D. Generally speaking, a laptop will underperform a desktop of the same relative components, by design. A laptop uses major components designed for lowe power and low heat. This translates to 'slower' than desktop components. Typical 'slower' components include: Memory Disk Video For instance: A mobile GForce 7950 GTX is NOT equivalent to a desktop version of the same card. Good Luck! -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
