RAM Speed...10 ns?????!?!

[troubledshooter]

Does changing RAM timing in the BIOS speed up the day-day access of RAM? I know I have 7.5 ns ram from micron, but in bios, my ABIT KT7 reports that the timing is set to 10 ns....does this slow anything down? Can I speed it up? This seems incredibly slow to me...


thanks!

 

[ltk007]

Yes it slows it down. I turned my ram to turbo and tried cas 2 and pc133, but it didn't like that. I run it at medium, PC133, and Cas 2

 

[troubledshooter]

I have read a lot of posts here about cas2-?? on ram settings, but in all my peeking at the bios of my Abit KT7, I have never seen this setting. Does anyone know if/where it is, and or can I just set the timing to like 8 ms? (I know the RAM is 7.5 certified as it is Mircron ($314!?!?! for 256 pc133) so the odds are low they pulled something shady)

thanks again!

 

[Insane3D]

I think the 2-2-2 designation is for Intel based mobo's.

 

[BigToque]

I dont know what its called in your mobo, but in my Abit BX6-2, the option is called "SDRAM CAS latency Time", under the BIOS option "Chipset Features".

the difference in performance of the 2 options is about 2-3%

 

[troubledshooter]

Ok....I'm getting warmer but I don't seem to be completely understood...

Can I simply lower the timing (from 10-8 for example) or do I have to find this "SDRAM CAS latency Time" feature?

thanks!

(More importantly, will it even matter!)

 

[BigToque]

When your talking about the speed of the RAM, thats bascially stating what FSB the ram can run at. If your RAM is rated at 7.5ns, then it should be capable of running at a FSB speed of 133 MHz. (1000/7.5 = 133)

The CAS latency time determines "The number of CLKs between when the SDRAMs a read command and when the controller samples read data from SDRAMs" (from BX6-2 manual). What I think this means is how long the RAM has to wait between each time the memory is read. Basically this means that if you set your CAS latency to 2, it has to wait less for data, which speeds up the performance of your computer.

 

[troubledshooter]

Thank you sir, a perfectly clear answer!

Does that mean however that if in BIOS my ram is telling me that it is set to 10ns that it is infact running at pc100 instead of 133?

thanks one last time! (hopefully)

 

[Auric]

The PC number is just a rating with which the manufacturer is stating their RAM will run at that FSB reliably. I think the actual latency generally being lower for higher FSB is incidental.

 

[Soccerman]

"Does that mean however that if in BIOS my ram is telling me that it is set to 10ns that it is infact running at pc100 instead of 133?"

sortof. what kind of computer are you running?

if you're running on a Via chipset, you may be able to get that RAM up to 133 Cas 3.

if you're on a BX chipset or something like it (synchonized FSB and RAM), then you can change the RAM setting in the BIOS so that it knows it's 7.5 (or whatever's the closest) nanoseconds. or you can adjust it manually. it will still be running at 100mhz, however the latency settings SHOULD be decreased automatically.

the 7.5 nanosecond speed means that you should be able to pump the RAM up to 133mhz. the latency settings are just a bonus so to speak. if yuo can get them lower (settings of 2), then you get more performance out of your RAM at the same mhz.

 

[Howard]

IMHO, this is because you're running a Duron system, which relies on a 100MHz bus. None of the Socket-A motherboards have the 4/3 memory divider, to my knowledge, so why would RAM be running at 133MHz? Your board probably doesn't detect potential speed/latency.

 

[JWMiddleton]

Hi TS,

I recently bought a new motherboard and moved my almost new Soyo 7VCA to another system. Both with PIII-700's. I kept the Micron PC-133, 256 MB,CAS-2 moduele with the new board (ASUS CUSL2) which will NOT run it at 133 CAS2, but will run at 129 CAS2.

When all of this was on the Soyo board I was running at 129 MHz FSB with the memory set to CAS2 and FASTEST. It would complete a SETI work unit (wu) in about 4 hours 45 minutes. When I moved the board I used memory from another machine that only allow me to run it at 133 MHz FSB, CAS3 and either NORMAL or MEDIUM as the memory speed. It extended my wu time to just under 6 hours. SO, memory timing does make a BIG difference!

 

[RSI]

RAM helps alot for SETI? heh.. didn't think it would, but oh well.

In my VA-503+'s BIOS I can set RAM to Normal, Fastest or Turbo.. I used to use Turbo all the time, but I keep it normal for stability, since I was having problems installing Win2K and stuff.

I have PC66 SDRAM which I think is "10ns".. I wonder if I lowered that by putting it to turbo.. but whatever

 

[troubledshooter]

I'm running a VIA kt133 chipset with an Award BIOS (Abit KT7, does this change anything?

thanks again!

 

[Soccerman]

yeah it means you can run your RAM at 133mhz, while your FSB speed stays at 100mhz (which means the CPU won't be overclocked).

then once you hit 133mhz, try different cas settings.

 

[Nih]

It's setting it at 10ns, because that is the default bios setting for the board/ram. tweak it to 3-2-2 , with the minus key or page up/down ,(or even 2-2-2)by the sounds of it. Just because the bios says 10 nano, there's no way that ram can't do better.

 

[troubledshooter]

Thanks a bunch everyone, from what I've seen faster RAM usually increases responsiveness more than anything, and since clicking the "set optimized defaults" button in the bios everything seemed sluggish...I'm going to have to go through and experiment with all this,

thanks for all the great help!