What determines OS speed?

[raiden-kun]

I would like to discuss the following: What makes a computer do typical OS functions faster?

Like opening windows, opening firefox tabs, switching between running programs, showing web pages(not counting the loading via Internet), etc.
(also not talking about things that would access the storage memory).


In my case I plan to one day own a machine that will perform these tasks at top speed.
However at the moment I have a Asus Eee PC 901 and I have to say sometimes it freezes for a little bit. For example, in the browser, when I press "open in a new tab" button in 3+ links, it gives me a small freeze, not related to internet connection loading but full computer freeze for a moment.
I don't think it happened many times, if ever, in my old AsusA7V8X-X.
So I compared the specs using CPU-Z:

.................................Eee901...A7V8X-X+AMD
processor:....................................................
core speed(GHz)...........1.6.........2.0...............
Bus Speed (Mhz)..........140........133................
Rated FSB (MHz)...........560........266...............
RAM:...........................................................
DRAM freq. (MHz)..........280........166...............
max bandwidth(MHz)....333........166.................
..............................PC2-5300....PC2700..........

Seams similar... Where do you think the difference is? Can cache memory be related this? GPU? other CPU features?

I also remember seeing an Asus motherboard for sale which stated on the box that would open websites extremely fast. So maybe chipset or other motherboard features?

Share your opinion

 

[acer0169]

ps3hacker beat me to it.

When I was younger I always assumed the CPU was the main bringer of speed to load times etc, then I decided it was RAM that did most of that. It didn't take long however to realise how important a fast hard drive is to a gaming machine.

SATA3 drives, along with SSD and PCI-E drives are the way forward, as they bring even slow computers back up to speed with very impressive load times.

Again as ps3hacker said, CPU helps with freezing or jerking motion when using basic applications, maybe you need some more cores for what you're trying to do?

 

[clarkjd]

I noticed that you didn't include the total RAM available to each platform. In my experience, the amount of ram available has a major impact on how well or fast a machine will perform. Once an application is loaded into ram, it will perform at its highest. The slowdown occurs whenever the machine has to perform some physical I/O(it has to read or write to a hard drive). Ram access speeds are an order of magnitude faster than hard disks(with the possible exception of SSDs). If the machine can perform its tasks without having to access a hard disk(this includes access to the swap file), it is performing at its best.

 

[hunter315]

Its often hard drive queries that slow a system way down, the OS will do its best to precache what it thinks you might want on the RAM, but if it runs out of space and you want to open up something else it has to write the contents of a block of RAM to the HDD, then load the new stuff onto the RAM which can take a second or two and is the main source of latency when you go to open up a web browser or application.

 

[ghnader hsmithot]

The way an OS is written is one of the most important features for it to be fast a easy to use.

 

[raiden-kun]

First of all, thank you for all your answers.
I find it interesting how everyone started to talk about SSD when I specifically said

also not talking about things that would access the storage memory

Anyways,

(...)for lag and freezing a CPU upgrade would help. but if you are talking about apps opening extremely fast your looking for an SSD.

I'm not talking about apps opening extremely fast. Boot times are completely irrelevant to me. I don't mind going to take a leak while the computer turns on or a heavy app is opening. As for the CPU being responsible for the freezes, that was my first guess too, but as I said, I had a computer with similar CPU and it didn't gave freezes. Unless you think 0.4GHz makes that difference.

(...)SATA3 drives, along with SSD and PCI-E drives are the way forward, as they bring even slow computers back up to speed with very impressive load times.

You don't have to sell me on high quality SSD's, I'm already a fan. Although I must warn you to watch SATA3 closely as they are often a bad deal. (A SATA2 SSD with read/write speeds maxed out is not extremely expensive and is compatible with almost every computer since most of us are using SATA2 compatible. While most SATA3 have not as good write speeds, read speeds just a bit better than SATA2, are more expensive and to get one you must first have a SATA3 compatible computer. If you want top speed get one of those PCI-e by OCZ that have SLC and insane speeds.)

(...)
Again as ps3hacker said, CPU helps with freezing or jerking motion when using basic applications, maybe you need some more cores for what you're trying to do?

I'm not trying anything, just talking about basic everyday OS operations. Obviously multi-core would be a huge difference. Dual-core vs Six-core doesn't make much difference, but single-core vs dual-core is a huge improvement. However I was talking about what other hardware features besides multi-core are important to OS operations.

I noticed that you didn't include the total RAM available to each platform. In my experience, the amount of ram available has a major impact on how well or fast a machine will perform.(...)

Since I never fill my entire RAM in everyday operations (even browsing with multitab), I don't think it is relevant. But if you want to know I have 1GB RAM size.

(...)Once an application is loaded into ram, it will perform at its highest. The slowdown occurs whenever the machine has to perform some physical I/O(it has to read or write to a hard drive). Ram access speeds are an order of magnitude faster than hard disks(with the possible exception of SSDs). If the machine can perform its tasks without having to access a hard disk(this includes access to the swap file), it is performing at its best.

You are very much right, however how do you make your machine load everything it needs into the RAM in order not to access the storage memory?

Ram access speeds are an order of magnitude faster than hard disks(with the possible exception of SSDs).

Ram access speeds are an order of magnitude faster than both top HDD and top SSD. I have actually done the math and even the most expensive SSD (in PCI-e and with all the crap) isn't nearly as fast as RAM, specially newer technology RAM.

Its often hard drive queries that slow a system way down, the OS will do its best to precache what it thinks you might want on the RAM, but if it runs out of space and you want to open up something else it has to write the contents of a block of RAM to the HDD, then load the new stuff onto the RAM which can take a second or two and is the main source of latency when you go to open up a web browser or application.

Again, is rare for me to fill my 1GB of RAM, and I think that's the case for most people (unless you are playing games of course). The question is: is the hard drive being used and slowing you down even when your RAM isn't full?

The way an OS is written is one of the most important features for it to be fast a easy to use.

I agree. But since I'm not willing to write my own OS and I don't plan to switch to any existing one, there's nothing I can do except improve my hardware.



PS: Just a couple of minutes ago I found someone talking about how the very example I gave actually needs to do writes in storage memory:

MLC based Solid State Drives all have one problem in common in that they have rather poor random write performance. As a result, operations that involve a lot of small random writes such as browsing websites with multiple tabs open or moving e-mail between folders in Outlook will often result in the system stuttering and stalling as it carries out the slow write operations.

I always thought browser tabs were only kept in RAM, since I always noticed how my RAM usage went up when I had a lot of them, but now that I think about it, all that crap I browse ends up on temporary folders so I guess it uses both storage memory and RAM.
Surprisingly enough, in the example I gave between my 2 computers, the random write thing might explain the freezes in my 901 since my old computer had a HDD with 25MB/s read&write speed while my 901 has a SSD with MLC with 36MB/s read & 9MB/s write, which is very slow write speed.

Any thoughts?

 

[clarkjd]

Since I never fill my entire RAM in everyday operations (even browsing with multitab), I don't think it is relevant. But if you want to know I have 1GB RAM size.

You are very much right, however how do you make your machine load everything it needs into the RAM in order not to access the storage memory?

Since you have only 1GB of ram (and NEVER fill it up) I am assuming you are not running one of the newer versions of Windows. Windows 7 requires 1 GB just for the OS(32-bit) or 2GB(for 64-bit). Windows XP about half that. What OS are you using? What zulfadhli said is true, the way an OS is written affects how well it uses memory and multitasks. Even Win7 requires a swap file(which is on disk) in order to run even if you have multi-gigabytes of ram, so I don't think you could simply get rid of the swap file and force Windows to keep everything loaded in ram. There will always be the "temporary Internet files" also on disk, because you never know how much data you will download from the internet.

 

[HEXiT]

keeping windows functions in ram will speed up your o.s.

 

[raiden-kun]

Since you have only 1GB of ram (and NEVER fill it up) I am assuming you are not running one of the newer versions of Windows. Windows 7 requires 1 GB just for the OS(32-bit) or 2GB(for 64-bit). Windows XP about half that. What OS are you using?

I am using Windows XP 32bits with some tweaks to consume even less RAM.

(...)What zulfadhli said is true, the way an OS is written affects how well it uses memory and multitasks. Even Win7 requires a swap file(which is on disk) in order to run even if you have multi-gigabytes of ram, so I don't think you could simply get rid of the swap file and force Windows to keep everything loaded in ram.

I thought the swap file/pagefile was only used when RAM got full. So I guess you are saying there's no way of keeping the OS from accessing the disk for basic functions because Windows accesses the pagefile all the time. Is that it?

(...)There will always be the "temporary Internet files" also on disk, because you never know how much data you will download from the internet.

Of course, no way around that I guess.

keeping windows functions in ram will speed up your o.s.

Can you give a practical example of that?


Thanks again

PS: For the record I think it might be possible to keep the OS from accessing the disk. Create a RAMDisk and install the OS into it, then everything would be in the RAM . But it would take a lot of RAM and you wouldn't be able to shut your computer down, only suspend.
Just a crazy idea, not much practical use really.

 

[clarkjd]

I am using Windows XP 32bits with some tweaks to consume even less RAM.

I thought the swap file/pagefile was only used when RAM got full. So I guess you are saying there's no way of keeping the OS from accessing the disk for basic functions because Windows accesses the pagefile all the time. Is that it?

I am using Win7 64-bit, with 8GB of ram. Windows still has a minimum size for the page file.

 

[runswindows95]

The main reason for your machine lagging is the N270 Atom CPU. It's a single core with hyper-threading. Also, uprgrading to 2GB will help. I've notice if the site uses heavy Flash, Firefox will easily eat up RAM. For what you're doing, a good build would be a Athlon X4 640 with 4GB of RAM.

 

[raiden-kun]

The main reason for your machine lagging is the N270 Atom CPU. It's a single core with hyper-threading. Also, uprgrading to 2GB will help. I've notice if the site uses heavy Flash, Firefox will easily eat up RAM. For what you're doing, a good build would be a Athlon X4 640 with 4GB of RAM.

1. I said these lags/freezes didn't happen in a slightly inferior processor.
2. As I said I never fill 1 full GB of RAM, even with heavy browsing, so upgrading it for bigger size is the same as throwing money out.
3. Windows XP 32bits would only use 3GB out of the 4GB you suggest