Teek22: Download the free version of Sandra.
This will be able to tell you exactly what speeds and timings your RAM supports - it reads the information from the RAM modules themselves and shows the supported speeds as well as what it's currently running at.
You may also get more information out of Sandra on exactly what motherboard, chipset, etc you have.
But I've never used it on a Dell, so I don't know exactly how much info you'll get.
Another useful tool you may want to download is memtest86 as this will allow you to easily test stability at different RAM timings.
Also, you may find this Dell™ Dimension™ E520 Service Manual of use.
From looking through that and the PDF of the user manual, it looks like you indeed can't alter you RAM timings, so, I would assume, if you mix your old RAM and your new RAM (and if they have different timings), your system will either a) not work or b) run at the timings of the slower ram. Which may or may not be as stable as running just the new ram at the either the correct or some other timings.
Unfortunately, RAM is one of those things where you can do all the research, make sure you're buying the 'right' RAM for your system, and still find that something about the interaction between the specific RAM you purchased and your specific motherboard means that it just will not run stably.
So, as I said before, the only way you're going to know, 100%, that they will work, is to buy some and install them.
This will be able to tell you exactly what speeds and timings your RAM supports - it reads the information from the RAM modules themselves and shows the supported speeds as well as what it's currently running at.
You may also get more information out of Sandra on exactly what motherboard, chipset, etc you have.
But I've never used it on a Dell, so I don't know exactly how much info you'll get.
Another useful tool you may want to download is memtest86 as this will allow you to easily test stability at different RAM timings.
Also, you may find this Dell™ Dimension™ E520 Service Manual of use.
From looking through that and the PDF of the user manual, it looks like you indeed can't alter you RAM timings, so, I would assume, if you mix your old RAM and your new RAM (and if they have different timings), your system will either a) not work or b) run at the timings of the slower ram. Which may or may not be as stable as running just the new ram at the either the correct or some other timings.
Unfortunately, RAM is one of those things where you can do all the research, make sure you're buying the 'right' RAM for your system, and still find that something about the interaction between the specific RAM you purchased and your specific motherboard means that it just will not run stably.
So, as I said before, the only way you're going to know, 100%, that they will work, is to buy some and install them.
Last edited by Scorpion0x17 (2007-06-19 15:03:32)