# How do I find the speed of my RAM? **URL:** \ **Category:** Factual Questions\ **Created:** [March 31, 2003, 4:36am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376 "2003-03-31T04:36:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 4:36am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/1 "2003-03-31T04:36:11Z")
I’m currently running both Red Hat Linux 7.1 and Windows ME (Ask for more specific info), so instructions germane to either or both OS are very much welcome here. 🙂 I wish to buy more RAM for my desktop PC. I was in the store, cash in hand, and I was brought up short when the salesman asked me what speed I needed. The salesman, to his credit, didn’t waste my money by selling me RAM when it was clear I had no idea what speed my motherboard would accept. So how do I find out what speed my motherboard supports? My PC has a PCI bus and an 800MHz AMD Duron CPU, and I have no idea how relevant that info is to my question. I’m, of course, willing to open the case if I know what I’m looking for. I’m betting there’s a simpler place to look, were I intelligent enough to think of it. I have checked the Control Panel under Windows, but I can think of no rational place to begin my search under Linux. ---
**Author:** ![diku](https://avatars.discourse-cdn.com/v4/letter/d/4af34b/32.png) [@diku](https://boards.straightdope.com/u/diku)\ **Post date:** [March 31, 2003, 4:37am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/2 "2003-03-31T04:37:40Z")
What type of motherboard? That would be a helpful clue. Model number if you know. Just a WAG, but I would say 133 SDRAM. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 31, 2003, 4:43am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/3 "2003-03-31T04:43:54Z")
Also remember that some PC manufacturers, like Compaq (I won’t tell you what I call them privately) use proprietary RAM chips. That said, there is a certain amount of backward compatibility so that you can use 133Mhz chips in a board with a 100MHz FSB, for example. As **diku** said, knowing which mainboard you ahve would go a long way towards being able to be more speciific. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 5:15am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/4 "2003-03-31T05:15:39Z")
Can I find out what my mobo is without cracking the case and looking for stickers? I want to do as much as possible before I unplug everything and go through all that hassle. 🙂 ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 31, 2003, 5:18am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/5 "2003-03-31T05:18:22Z")
Unless it’s one you built yourself, I ought to be able to pull RAM info from the make and model of the PC. ---
**Author:** ![Number](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/number/32/242_2.png) [@Number](https://boards.straightdope.com/u/Number)\ **Post date:** [March 31, 2003, 5:19am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/6 "2003-03-31T05:19:53Z")
I don’t know of any way to detect the RAM speed through the operating system, but you can usually tell in CMOS setup. Is this a brand-name PC like Dell or Compaq? If not you’ll have to open the case and look at the motherboard. Once you know the PC or board model number, look it up at [www.crucial.com](http://www.crucial.com). It will tell you how much and what type of RAM your machine will accept. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 5:23am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/7 "2003-03-31T05:23:58Z")
Thank you. This box’s OEM is Compaq (A Compaq 5001CL, in fact), and I’ll now shut up and look at the link **Number** provided. Thank you. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 31, 2003, 5:29am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/8 "2003-03-31T05:29:58Z")
**Number** ’s link appears down. Try [this one](http://62.108.128.97/index.asp?classid=100&mfrid=25) instead. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 5:41am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/9 "2003-03-31T05:41:17Z")
I’ve followed the link and found the info, **Q.E.D.** , but I still have some uncertainty. Is the 200MHz FSB mentioned at the webpage the correct speed? Or will I have to buy from the webpage to be sure? 😃 Thank you for all your help, I’m just a little slow when it comes to hardware issues. ---
**Author:** ![Willy\_ph](https://avatars.discourse-cdn.com/v4/letter/w/ea5d25/32.png) [@Willy\_ph](https://boards.straightdope.com/u/Willy_ph)\ **Post date:** [March 31, 2003, 6:35am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/10 "2003-03-31T06:35:33Z")
You could find out what the speed of you installed ram is by downloading Sisoft Sandra. I’m pretty sure that it will identify the amount, type and speed of your installed ram. Plus, it shows alot of other information about your computer that can come in handy sometimes. ---
**Author:** ![Willy\_ph](https://avatars.discourse-cdn.com/v4/letter/w/ea5d25/32.png) [@Willy\_ph](https://boards.straightdope.com/u/Willy_ph)\ **Post date:** [March 31, 2003, 6:38am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/11 "2003-03-31T06:38:31Z")
I just checked you requirements. You’ll need to buy PC100 ram. 200mhz is the Front Side Bus speed and doesn’t have much to do with your ram. (Or at least for you purchasing requirements.) ---
**Author:** ![Willy\_ph](https://avatars.discourse-cdn.com/v4/letter/w/ea5d25/32.png) [@Willy\_ph](https://boards.straightdope.com/u/Willy_ph)\ **Post date:** [March 31, 2003, 6:39am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/12 "2003-03-31T06:39:33Z")
Just make sure you buy PC100 ram. You can purchase it from any computer store (online or b&m.) ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 6:54am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/13 "2003-03-31T06:54:39Z")
Thanks. Is 100 the speed, then? How is it measured? I’ll toddle off to Google and download Sisoft Sandra. Thanks for all the help. 😃 ---
**Author:** ![Willy\_ph](https://avatars.discourse-cdn.com/v4/letter/w/ea5d25/32.png) [@Willy\_ph](https://boards.straightdope.com/u/Willy_ph)\ **Post date:** [March 31, 2003, 7:06am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/14 "2003-03-31T07:06:43Z")
mhz. In your case, the ram is operating at half the speed of the FSB. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 31, 2003, 7:49am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/15 "2003-03-31T07:49:56Z")
Ok. Sandra confirmed that my RAM is operating at 100MHz. Thank you for your help. ---
**Author:** ![Alereon](https://avatars.discourse-cdn.com/v4/letter/a/ecd19e/32.png) [@Alereon](https://boards.straightdope.com/u/Alereon)\ **Post date:** [March 31, 2003, 1:20pm UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/16 "2003-03-31T13:20:55Z")
A note on RAM: Just because its running at 100Mhz doesn’t mean its PC100. Most AMD systems used PC133 SDRAM, sometimes clocked at 100Mhz instead of 133Mhz. Sandra will be able to read the SPD chip and tell you what the RAM is rated at. Either way, you’ll definitely want to purchase PC133 SDRAM, NOT PC100. It will be cheaper than PC100 and more widely compatible. If have only a small amount of RAM, say 128MB or less, it would be advisable to simply replace your RAM with good quality CAS2 PC133. This will result in a performance increase of between 10% and 15%. Your motherboard may also dislike it if you mix different brands of RAM, or if you fill several slots. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 31, 2003, 1:26pm UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/17 "2003-03-31T13:26:47Z")
> [@](#): > > \*Originally posted by Alereon \* > \*\*A note on RAM: Just because its running at 100Mhz doesn’t mean its PC100. Most AMD systems used PC133 SDRAM, sometimes clocked at 100Mhz instead of 133Mhz. Sandra will be able to read the SPD chip and tell you what the RAM is rated at. Either way, you’ll definitely want to purchase PC133 SDRAM, NOT PC100. It will be cheaper than PC100 and more widely compatible. > > If have only a small amount of RAM, say 128MB or less, it would be advisable to simply replace your RAM with good quality CAS2 PC133. This will result in a performance increase of between 10% and 15%. Your motherboard may also dislike it if you mix different brands of RAM, or if you fill several slots. \*\* He’s got a Compaq. He better get whatever Compaq specifies, or it most likely _won’t_ work. He doesn’t necessarily have to buy it _from_ Compaq, but it better state that it’s Compaq RAM in the product description. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [March 31, 2003, 3:00pm UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/18 "2003-03-31T15:00:33Z")
I second **Q.E.D.**'s warning. I had a Compaq at work, and the “power-supply” failed. Instead of buying a standard replacement part for $50 at any good supplier, we had to buy a Compaq-specific part for $120, _and_ pay labour to a Compaq tech to install it. It was a different _shape_. Sheesh. We now use Dell. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [March 31, 2003, 3:27pm UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/19 "2003-03-31T15:27:40Z")
Just open the box, take out a chip if you can, take it to the store. Some computers require two matching chips to work anyway. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [April 1, 2003, 2:07am UTC](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376/20 "2003-04-01T02:07:17Z")
Hm. So I’ll need to find out if it’s Compaq-compatible? What if I don’t? (Or, how can I diagnose the problem if I buy the wrong kind and use it anyway?) [Next page](https://boards.straightdope.com/t/how-do-i-find-the-speed-of-my-ram/165376.md?page=2)