# Difference between Rdram and DDR memory
**URL:** https://boards.straightdope.com/t/difference-between-rdram-and-ddr-memory/321013
**Category:** Factual Questions
**Created:** [September 10, 2005, 7:58pm UTC](https://boards.straightdope.com/t/difference-between-rdram-and-ddr-memory/321013 "2005-09-10T19:58:03Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)
#### Post date: [September 10, 2005, 7:58pm UTC](https://boards.straightdope.com/t/difference-between-rdram-and-ddr-memory/321013/1 "2005-09-10T19:58:03Z")
While I can fix a wide range of problems in computers, I never did really read up on memory. What’s the difference bwteen DDR and rdram memory? And what is considered normal as far as memory speed today?
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### Author:  [@Catalyst](https://boards.straightdope.com/u/Catalyst)
#### Post date: [September 10, 2005, 8:08pm UTC](https://boards.straightdope.com/t/difference-between-rdram-and-ddr-memory/321013/2 "2005-09-10T20:08:15Z")
> [@smiling bandit](#):
>
> While I can fix a wide range of problems in computers, I never did really read up on memory. What’s the difference bwteen DDR and rdram memory? And what is considered normal as far as memory speed today?
The Wikipedia entries on [RDRAM](http://en.wikipedia.org/wiki/RDRAM) and [DDR SDRAM](http://en.wikipedia.org/wiki/DDR_SDRAM) explain it better than I can.
As for the current “average” RAM speed, my guess would be that either DDR333 or DDR400 is the most common, though DDR-2 sales are expected to surpass DDR-1 sales in the not-too-distant future.
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### Author:  [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)
#### Post date: [September 10, 2005, 8:41pm UTC](https://boards.straightdope.com/t/difference-between-rdram-and-ddr-memory/321013/3 "2005-09-10T20:41:24Z")
Obviously I want to match my memory speed ot my front-side bus. I’ll have to dig around and find out what that is…
Thanks! Great article, though I didn’t quite understand how the double-pumping process works even after reading the article. (I’m a techie, but I’m not that good).