How much Memory?

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

I recently purchased a refurbished Dell Inspiron 518 with 6 gigs of RAM and 64 bit Vista. It works very well editing large files, videos, etc. (Sorry to disagree, Doc, but I have had several refurbished Dells, and have been satisfied with every one after getting rid of the crapware)

Anyway, here is the question:

The computer has 4 memory slots, each of which is supposed to be capable of accommodating 2 Gig PC6400 DDR2 SDRAM cards.

The instruction manual (obviously written before this computer was delivered with 64 bit operating systems) says there is a 4 gig limit on memory. But Dell never (apparently) delivered this computer with more than 6 gigs, even when equipped with Vista 64.

My question: what is the likelihood that 8 gigs will work properly? The computer is presently equipped with 2 2gig DIMMs and 2 1gig DIMMs. I am tempted to replace the 1 GIG DMMS with 2 GIG, but don't want to spend the money if there is a good reason why it won't work. I can think of no reason why it won't.

What do you guys think?

PhotoCarp · Joined: Sep 06, 2007 Posts: 109

I would buy the memory and return it if it doesn't work. Before you make the purchase check the store's return policy. Remeber, it will be far easier to return it to a local brick and mortar store than an online store and you won't have to pay shipping.

As for Dell, I also have been a satisfied owner through the years. I bought my first Dell about 13 years ago. To date I've had 2 desktops and 4 laptops and only had a problem with one laptop hard drive. Refurbished models are usually in better condition than new because, in most instances, they will give them a more thorough going over than one rolling off the assembly line.

goretsky · Posted: Mon Jun 29, 2009 12:35 am Post subject:

Hello,

The Dell Inspiron 518 uses the Intel G33 chipset. According to this white paper on Intel's web site, the maximum amount of RAM which can be addressed by the G33 chipset is 8GB (see Section 3.1 Memory Technology Supported).

The G33 chipset works with both DDR2 and DDR3 memory. According to this page on Crucial's web, the Dell Inspiron 518 uses DDR2 memory (they also say it is limited to 4GB, which we know is incorrect). You should just be able to purchase two 2GB DDR2 memory modules with the same speed and timing of your existing pair of 2GB memory modules, and be up and running in no time.

Regards,

Aryeh Goretsky

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

Thanks guys. I will purchase 2 matched 2GB ram modules in the next few days and report on the results.

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

OK. I bought 2 matched 2GB 800GHz memory modules.

The good news: Bios now shows 8 GB of memory, as does Windows.

The bad news: The Bios reports that memory speed is now 667 MHz.

Up to 6 GB the memory runs at 800.

Goretsky: is this a characteristic of the Intel chipset? Or is my new 800MHz memory not being recognized as such. In any event, the Bios does not allow adjusting these speeds, unlike other bios I have had.

kenmabmcc · Posted: Wed Jul 01, 2009 6:16 pm Post subject:

If your other modules run at 667,
your new modules will default to that speed.

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

Another experiment: Used the Corsair modules with the old 1Gb modules for a total of 6 GB. Still had 667 MHz memory speed. The lower speed seems to go with the Corsair modules rather than with memory size.

What to do? Take them back? Pay more for other memory modules? Buy

the modules from Dell at exorbitant prices?

thanks

BTW: the modules are TWIN2X4096-6400C5C G

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

kenmabmcc

Have you tried it with just the new modules in ?

goretsky

Hello,

My initial thought is a memory latency timing issue with the Corsair TWIN2X4096-6400C5C memory. The timing for this memory is 5-5-5-18, according to Corsair's web site, and it could be that your computer does not currently support this memory timing.

That is usually handled through the computer's BIOS firmware, so you might want to make sure that you have the latest version of the BIOS installed for the Dell Dimension 518. BIOS release 1.0.8 can be found here on Dell's support web site.

If that does not solve the problem, I would suggest looking in the BIOS to see if you can manually set the speed and timing for the memory. Corsair technical support may have some additional suggestions as well.

Regards,

Aryeh Goretsky

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

A bit more information. I communicated with Dell support. They said that while the memories have the same specifications, due to being of different manufacturers, the timing may be a bit off, and so the system backs off to the next lower clock rate. Solutions would be to use only Corsair RAM, or only Dell Ram. My choice.

Does this seem reasonable?? In the past I have never had problems mixing different manufacturers of the same specification memory. But then, clock speeds were much slower.

goretsky

Hello,

That sounds correct to me.

Recent designs of memory modules have an EEPROM-like chip on them called the Serial Presence Detect (SPD) chip that, amongst other things, stores the various operating frequencies and timings at which the memory chips on board operate.

When the computer is started, the motherboard's BIOS firmware checks the SPD data and selects the fastest set of settings that are common across all of the installed memory modules. In your case, the 667MHz speed (and associated timings) are the fastest available.

Some motherboards let you manually set the timings and bypass the SPD data in the BIOS settings, but this does not sound like an option for the Dell Inspiron 518.

I would suggest using the motherboard with 8GB at 667MHz for the time being, and if you find that speed of the memory is insufficient, replace the factory-installed memory modules with another Corsair TWIN2X4096-6400C5C set.

Regards,

Aryeh Goretsky

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor

Final follow up:

I returned the Corsair memory and bought Dell Memory. That worked. I now have 8Gb running at 800MHz.

Thanks everyone for the advice.

goretsky

Hello,

How does the system perform with 8GB of RAM?

Regards,

Aryeh Goretsky

bern · Joined: Mar 12, 2007 Posts: 1432 Location: ann arbor