Ram Question?

Gigabyte / Ga-ma785g-ud3h
February 5, 2010 at 10:47:33
Specs: Microsoft Windows XP Professional, 3.013 GHz / 2046 MB
I'm trying to clear something up in my feeble little mind. I'm using an Athlon X2 250 regor dual core processor on a Gigabyte GA-MA785G-UD3H Mobo. The info I have from reading is that the X2 250 has a memory controller for DDR2800 PC6400 memory (which I am using in dual channel mode / 2 gigs} or it has support for DDR3 PC38500 ram. My Mobo doesn't support DDR3, so should I and do I have to use the DDR2 800 PC 6400 ram? Right now with the current ram, it's running a perfect 1:1 ratio. Also, does anyone have a good site to recommend that explains ram and processor speeds. It's confusing to me. Thanx.

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February 5, 2010 at 11:21:23
There is no ratio to be concerned about because there is no FSB. Obviously you can't use DDR3 because your motherboard doesn't support it. DDR2-800 running at 400MHz frequency is the best choice. You'll lose a little performance by running DDR2-667 at 333MHz frequency, but the difference in minor. What speed RAM do you have?

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February 5, 2010 at 11:26:26
Hi Jam, I'm using DDR2 800 PC 6400 made by Nanya. 1.8 volts 5-5-5-18 timings. 2 gigs in dual channel mode.

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February 5, 2010 at 19:03:02
Might be able to overclock the memory if you want to try to up it to 1066. Add some volts.

Might smoke the whole deal too. It should be OK for most things as it is. It will run Virtual Machines nicely.

Playing to the angels
Les Paul (1915-2009)

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Related Solutions

February 5, 2010 at 19:29:40
For most if not all mboards that use DDR2 ram only, the memory controller is built into the CPU (at least it is with 64 X 2 and up AMD cpus - I'm no Intel expert), not the mboard's main chipset. In that case, it's the CPU's memory controller the ram has to be compatible with, so the same ram, at least 800mhz DDR2 and below, should work with any recent or fairly recent mboard that has the memory controller built into the cpu (at least the 64 X 2 and up AMD CPUs) that requires DDR2 ram. 1066mhz DDR2 ram seems to be more finicky to get to work, possibly mostly because of the following.

Some ram manufacturer's modules do not strictly adhere to the JEDEC standards that most mboards use to determine ram settings.
In that case, the ram settings in the bios Setup that the bios has automatically chosen may not be correct.
Check the ram setting in your bios - the ram voltage, and the ram timing numbers - those should be the same as for the specs for modules themselves. Often the ram voltage and timing numbers are printed on the label on the modules.

If the voltage setting or timings settings in the bios are different from the specs for the ram, change them in the bios. The timing numbers must be as close as you can get to the same, or slower timings (higher numbers = slower) - you won't notice the difference the lower settings make.

If you have a mix of different modules
- don't mix ram that specifies different voltages - the bios will force the ram to use the lowest voltage, if "by spd" or similar is used (default settings) - ram that specifies a higher voltage is more likely to not work properly in that situation.
- the bios settings must be those for the slowest timing settings of all the modules, or slower (higher numbers = slower).

In your case the ram voltage is the same as the JEDEC standard

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February 6, 2010 at 04:39:20
Hi Jefro and Tubes,
Thanx for the replies. I'm not going to overclock the ram. Right now it's running at a perfect 1:1. I just ordered 4 more gigs from Newegg. I'm going to remove the existing 2 gigs of Nanya and install the new Crucial 4 gigs. When I decide to use Win 7, I'll reinstall the other 2 gigs for a total of 6 gigs. The nanya and Crucial have the exact same voltage (1.8) and timings, so i don't see a problem there. Thanx again.

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February 6, 2010 at 10:29:37
If your XP Pro is not the 64bit version, you can't actually use all of the 4gb, or all of any amount greater, in Windows.

32 bit Microsoft operating systems (2000 and up) have a 4gb virtual memory address limit - for both the ram and the requirements of Windows.
When you install 4gb, or more, depending on the system and whether you're using onboard video or not, Windows can only actually use anywhere from a little under 3gb to a little over 3gb when you install 4gb of ram. Windows itself uses up some of the virtual memory address space the ram needs when you have a 32 bit operating system in that situation.

If you want to be able to get Windows to use all of 4gb or 6gb or more in Windows 7, get a 64 bit version!

Buying OEM Windows 7 64 bit or 32 bit is the cheapest way of getting a single licence copy. It's not a retail version. You can get it on the web, or some local places that repair and build custom computer systems and have lots of parts and software sell it. OEM in this case = you get no free Microsoft phone or other technical support - you provide your own support. You can buy it from TigerDirect without having to buy hardware along with it, but otherwise you need to buy it along with something essential for a computer - e.g. a case power cord will do.

By the way, not all software that runs in 32 bit Windows will run in 64 bit Windows, and lots of program versions are STILL not compatible with Windows 7, even when they are compatible with Vista !

Most people DO NOT need more than 3 or 4 gb, and DO NOT need to run a 64 bit operating system !

Ultimate Memory Guide
How Much Memory Do You Need? etc.

Windows98 and up, to Vista, Linux, Mac
No mention of Windows 7.

Memory Assessor
How much memory do you really need?
NT Workstation and up
Windows 7 is there.

E.g. A real life example.

I tried both 3gb and 4gb of PC6400 ram on a friend's system that's running XP Home.
I bought the ram in two matched pairs at two different times for him - same maker, same non JEDEC voltage ( 2.0 ? ) , slightly different timing specs.
The bios was set right for the combo by default - I checked.

He's using a Radeon 4850 video card (wow !) , and an Athlon 64 X2 6400+ cpu (the top of the original ones) , on an Asus AM2+ mboard model that was new two years ago or less. It has onboard video but that was auto disabled when he ( I did it for him ) installed the video card.

I looked at System Information under the same conditions.

- When I installed 3gb of ram, in System information I saw there was a bit more Available Physical Memory, than there was when I installed 4gb of ram !
- The system NOTICABLY ran better with 3gb rather than 4gb !

It told the computer owner his system ran better with 3gb rather than 4, and I left only 3gb installed, but he's computer STUPID and installed the 4th module later anyway.

If you don't believe your computer could run better with 3gb than it does with 4gb with a 32 bit operating system, run some third party performance tests with 3gb and 4gb to compare the two situations.
E.g. Sisoft Sandra.
3 modules of DDR2 ram can't run in dual channel mode on most computers, but that's a very minor concern. In the real world having all the ram running in dual channel mode results in at best a few percent performance increase - it's marketing hype.
You get much more of a performance increase, if you actually have programs that run better with more ram (most people do not, after a certain amount of ram is installed), by installing more ram, or, probably, according to my experience, by installing 3gb rather than 4gb of ram (or > 3gb but less than 4gb), in a 32 bit operating system.

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February 6, 2010 at 10:40:04
OK, Tubes. I appreciate the info. I know windows xp won't use all the ram, but if it uses 3 to 3.5 gigs, that's ok. I mainly got the ram for a Win 7 upgrade in the future. Thanx for the reply, you're always so detailed. You must like to type :))

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February 6, 2010 at 10:52:30
"You must like to type :))"

Not really. I'm a terrible typist.
I do it because I'm a Virgo and I just MUST explain things thuroughly.
I have a lot of text in files on my computer that I copy rather than type it from scratch every time.
FYI most of the stuff in the posts I made in this Topic was typed from scratch.
One of these days I'll install the Dragon Naturally Speaking 10 that I just bought on my XP computer, which is presently loaned out while I am working on a friends computer at home.
I have version 9 too, but haven't installed it either.

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February 6, 2010 at 10:58:37
Well, that explains a lot. I didn't figure you would do all that typing for every post. You do a good job of explaining things and you are thorough. Keep up the good work.

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