On Tue, 9 Apr 2002, Christopher P Wright <softpixel.com> wrote: > > I have general questions regarding a typical Linux system's speed and > > wonder this is right place to ask these questions. If this is not, Could > > someone point out which group I can post. > > probably not the best place, but i know of nowhere else. > > > With following typical components on a motherboard: > > 512 MB 10K RPM DRAM, > > Intel 850 chipset with 64-bits Data bus width and 400MHz Data Rate, > > 32-bit/64-bit PCI 2.10 bus (33MHz/66MHz) > > 20 GB Hard Drive > > i think the 10k rpm goes with the harddrive, as dram doesn't rotate =) > > > Does Intel 850's 400MHz data rate fully used or not on 66MHz bus > > speed? As speed of these components are measured by rates, I am > > wondering how one can evaluate the system's speed roughly in terms of > > using MB/sec so that one can see potential bottleneck or trend of > > improvement. On Windows, using PCMark2002 benchmark software from > > MadOnion.com, one can see 20-70 MB/sec on HD, 700 - 1,400 MB/sec on > > DRAM. Is there a way one can measure system bus actual speed under > > Linux or benchmark for DRAM, HD? > > the 400Mhz is the dram clock. 66Mhz is standard pci (as is 33 sometimes). > obviously, the 400Mhz would not be used fully from a 66Mhz feed. this is > typical. (memory is faster than pci cards, etc). the 400 Mhz is the speed at which your Ram works, I think it's Rambus memory and that you are using a P4. a P4 core has a bus of 100 Mhz quad pumped, so ram and cpu are in sync. in a usual system these days the pci speed is 33 Mhz and for servers with 64 bit pci slots the speed is 66 mhz > > to test HD performance one can use 'hdparm -T -t'. that benchmarks hd > speeds, and buffered reads (sort of memory bandwidth maybe?). im not sure > of a tool to measure dram bandwidth directly, but i'm sure they exist > somewhere. be sure to enable dma on the harddrive before you benchmark > it, or the speeds will be worse. ( 'hdparm -d1 [device]' ) > > > In addition, if I like to add a 1GB Network Interface Card for > > clustering two same machines, should I add a 32-bit NIC card or 64-bit > > NIC in terms of performance, and why? > > 64bit would generally be able to transfer data to/from the system twice > as fast as a 32bit card, simply because it transfers twice as many bits > per cycle. i think 64 bit may be clocked higher (the 66mhz) than the 32 > bit (33 mhz???) but i'm foggy on pci specs in that regard, someone else > probably knows far more in depth. i should go for the 64 bit cards, they have a lot more throughput but it depends on the connection you are using, on a 100 Mbit network you can get speeds of as high as 12 MB/s but, since you can transfer up to 133 MB/s over a standard 33 Mhz pci bus you still have a margin. There is a small ap called memtest (look on freshmeat.net) that tests your Ram for faults and it has the advantage that it measures and shows the speed of your ram and cpu cache. you compile it, copy it to a floppy and boot with it. hope this will help you (correct me if I'm wrong :) ) greetz stijn > > ttyl > chris > > -- > "In other words, I'm lost, don't know where we are, > where we're going, or even if we're going anywhere, > and don't have control anyway. Otherwise everything's fine." > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
