I have an HP Pavilion a520n machine with 2-256mb ram modules, 184 pin ddr sdram, pc2700 333mhz non-ecc raring. Per hp spec and motherboard spec. It's expandable to 1 gig ram max per HP, although the motherboard allows 2 gig max.
There are 2 ram slots on board.

I want to upgrade the ram to 2 -512mb modules.

When going out to the crucial and kingston sites configurators, I'm pointed to ram that has a cl rating of 2.5.
Kingston has a HyperX 1 gig set (2-512mb) with a cl rating of 2 that I'd liked to put in my machine. The problem is that this ram is not given as a selection for my machine from Kingston.

May this be a problem running on my machine? All business related activities and such.

Should I not deviate from the configurator recommendations?

Is the extra money for the cl2 rating worth the price difference? $24.00 upcharge for the set.

What about some of the less expensive brands RE: PQi

The range is from $46.00 to $70.00 for 1 set of 2-512mb modules.

I've been trying to figure this out but am stumped.

Thnaks for your help.


I'd recommend buying 2 inexpensive 512MB DDR400 modules. DDR400 gives you some overhead. On an HP PC, you will not be able to tweak memory timing which is usually required to actually get lower latencies.

Odds are that you won't notice any difference between CL2 and CL3 memory in your PC.

I use A-Data and PQI for inexpensive RAM and have had good results with both. When reliability is critical, I use either Crucial or Corsair.

I assume then, that the 400mhz will work well with the 333mhz sytem? By overhead I'm not sure what you mean.

Thanks for coming back to me.

One other questions too. I assume that 400mhz pc3200 module will fit into the slots and be seen by the motherboard as pc2700 and operate as 333mhz?


You assume correctly.

Higher speed RAM can usually be tweaked to run with more aggressive timings when installed on a PC with lower bus speeds. There's a better chance that 2.5 CL memory will actually run at that setting.

As I said earlier, there won't be any tweaking on a Pavilion. The best you can hope for is that SPD on memory is accurate and BIOS will use SPD information.

Even though the Pavilion is not dual channel, should I purchase a dual channel set to confirm matched speeds with the ram.
Does the 400mhz ram work because the motherboard is rated at FSB speed of 400mhz?

Questions, questions, questions :)

Memory will usually "downshift" to work with lower bus speeds.

I'd buy a dual channel set to save on shipping costs if purchased at Newegg. Dual channel memory is not necessary, but not a bad move either.

Here's my recommendation:

I'll follow your suggestion and purchase this morning.
Sorry for all the questions. Inquiring minds like to know. :)

Thanks for your time and input.

Mucho Gracias Senoir

You're welcome. When purchasing memory, stick with Crucial, Corsair, and Kingston - you'll be glad you did. All 3 are very reliable.

What about G.skill?

I just purchased some for another machine and will install today.

No personal experience.

Installed it and it's working fine.

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