Sdram Cas Latency Time

Hi Everyone,

not a real problem but rather a curiosity of mine... AWARD modular BIOS v4.51PG/Win98SE:

as soon as my PC is switched on, after POSTing I'm always reading the following msg on the screen:

Suggested SDRAM CAS LATENCY TIME is "2 "

...well, what does that mean? something to worry about? I'm wondering if there is any BIOS setting I should change or it's just an harmless info I'm getting...

I'd like to learn more about it...of course any good suggestion is welcome!

 

It is a setting in the BIOS.

Do a search at www.google.com for "CAS Latency Time ".

 

Thx for your time Alex but what I'd really like to know is if I should change that setting (fro "3" to "2 "...) or if I had better not alter it...
Moreover, browsing throughout the Award Bios Chipset Features Setup menu, I can't find any reference to CAS Latency Time feature at all...

 

Yes, and No. It's a BIOS setting that makes memory performance a very small amount faster, & can quite often cause a lot more problems with stability. But that is usually the case of over-clockers running CAS-3 ram at CAS-2.

With your BIOS message it appears that you are running your BIOS with settings which has set CAS to a safe 3 & your ram's SPD info is telling the BIOS that it's CAS-2.

It really makes very little difference to performance but to eliminate the annoying message try setting the memory CAS setting to Auto (or set it to 2 if ALL your memory is the same).

Sounds like you've changed RAM or someone's been playing the BIOS settings because Default/Setup settings or Optimised settings in the BIOS should usually set most things to Auto, including the memory's CAS rating.

 

"Fast RAS to CAS Delay" and/or "SDRAM (CAS Lat/RAS-to-CAS) ".

Anything with a setting choice like "x333/x444" or "3 Clks" or "3/3" can be changed to lower numbers.

 

Dave, thx for the reply...I really added a new 64 MB RAM module about 3 months ago but I was already reading that msg long before and I didn't mind it till a friend of mine called my attention to it...

Since I've no idea if my memory is all the same,I think I'll not change that value: after all, if "it really makes very little difference to performance" as you say... well, better safe than sorry !

BTW the list below shows ALL the current default values (...I never changed any of them!) of my Award BIOS Chipset Features Setup Menu:

• Bank 0/1 DRAM Timing : SDRAM 10ns
• Bank 2/3 DRAM Timing : SDRAM 10ns
• Bank 4/5 DRAM Timing : SDRAM 10ns
• SDRAM Cycle Lenght : 3
• DRAM Clock : Host CLK
• Memory Hole : Disabled
• Read Around write : Disabled
• Concurrent PCI/host : Disabled
• Video RAM Cacheable : Disabled
• PCI Dynamic Bursting : Enabled
• PCI Master 0 WS Write : Enabled
• PCI#2 Access #1 Retry : Disabled
• AGP Aperture Size : 128M
• AGP-2X Mode : Enabled
• OnChip USB : Enabled
• USB Keyboard Support : Disabled

...no reference to CAS or RAS or Latency Time, as you can see...

 

Your motherboard manufacturer must have decided to not allow user access to change these settings in Default/Setup mode. If you set the BIOS to Optimised Defaults it "may" add options to allow you to change extra settings.

But like you've noted, it's not really a problem - if you can ignore the message - as you're not missing out on any noticable extra performance (it's rarely even measurable). In fact it should be more stable.