RAM CL: upgrade or start from scratch?

[jacksie]

i have a dell xps 420 with vista 32bit (that might change to 64bit in near future). i have 2x1gb ram that came with the computer, according to everest, the details being:

Module Name Nanya NT1GT64U8HB0BY-25D
Module Size 1 GB (2 ranks, 4 banks)
Module Type Unbuffered DIMM
Memory Type DDR2 SDRAM
Memory Speed DDR2-800 (400 MHz)
Module Width 64 bit
Module Voltage SSTL 1.8
Error Detection Method None
Refresh Rate Reduced (7.8 us), Self-Refresh

Memory Timings:
@ 400 MHz 6-6-6-18 (CL-RCD-RP-RAS) / 24-42-3-6-3-3 (RC-RFC-RRD-WR-WTR-RTP)
@ 333 MHz 5-5-5-15 (CL-RCD-RP-RAS) / 20-35-3-5-3-3 (RC-RFC-RRD-WR-WTR-RTP)
@ 266 MHz 4-4-4-12 (CL-RCD-RP-RAS) / 16-28-2-4-2-2 (RC-RFC-RRD-WR-WTR-RTP)

so it seems my cl settings are 6-6-6-18. i have no idea what sort of performance difference this makes from the preferrred 4-4-4-12. is it night and day difference or is it 5% extra performance for those who have the time and knowledge to tweak settings and overclock (which i wouldn't be doing) ?

what do you think, should i:

- just install 1 cheaper crucial 2x1gb kit with cl=6 (link: http://www.crucial.com/uk/store/mpartspecs.aspx?mtbpoid=3AC04C87A5CA7304

- or start from scratch and get 2 ballistix kits (or something comparable from another brand) with 4-4-4-12 (link: http://www.crucial.com/uk/store/mpartspecs.aspx?mtbpoid=8B4F22F4A5CA7304

the 2gb addition would set me back 40 quid, the 4gb 'start from scratch' would be around 120 quid. i'll pay the difference only if it will really be justified.

final question: i know vista 32bit won't use all 4gb, but would there be any problems to stability ?

thanks!

 

[RetiredChief]

1) 4gb - Should be no problem with stability. As for usage, XP/Vista 32 bit WILL utilize upto 4 Gigs of ram, it is just that when 4 gigs are installed only 3.2 +/- 0.4 gigs are available for programs. This has been addressed in several treads, if you would like to read more on this subject.

As far as performace going from CL6 to CL4, There is a boost, going by what I've seen in some of the threads gains are greater for AMD X2 procs than Intel dual's. I think the perforance gain going from CL5 to CL4 is around 3 to 5%. Going from 6 -> 4 would probably be in the neighborhood of 12% +/- 5%

 

[sailer]

In principle, going from 6-6-6-18 to 4-4-4-12 will increase the speed a fair amount, enopugh to be worth it in my opinion. But the Ballistic ram that you list gets its speed by using a higher voltage, 2.2V, and from what I've read, Dell computers don't allow a person to raise the ram voltage. The result is that the ram ends up running at 667 (PC5300) instead of 800 (PC6400), thus being slower. So in your case, the cheaper and slower ram (cl6) would be your best option because it runs at a standard voltage of 1.8V.

 

[jacksie]

thanks.

i read up and confirm dell mobos can't have the voltage changed. probably would not have gone for the more expensive option anyway given marginal improvement. ordered the cl=6 kit.