Determining RAM speed

[GreenwoodGuy65]

Hi all

 

I have a question regarding RAM speed. I have 1G DDR400 and have been trying to oc my AMD3000. I have it at 2.2Ghz right now with a DRAM speed of 166mhz. I have tried setting it to 180 or 200mhz, but with my current multi and fsb (9X and 250mhz resp) the system won't post.

 

So, when I run memtest from within the bios, the test reports that, with the current speed of 166, the effective speed is DDR409 or so. But, when I boot the system and look at the post, the report is DDR333.

 

So, am I running at 333 or 409? Everest reports 409 as well, but I think that it is actually running at DDR333, as I haven't selected 200mhz in the dram settings.

 

Yes, I have read the AMD64 overclocking guide and that is how I got my fsb to 255.

 

Thanks, and sorry if this post should have been in my other post "Pushing past 1.9Ghz"

[Syngensmyth]

Your ram is probably SPD of 333 a sort of stock rating. If you set FSB to 200 your ram will run 400 (the old AMD doubling everything trick). If set divider then ram will run slower than FSB.

 

Use CPUZ to determine what is really happening. Notice the "Memory" and "SPD" tabs.

[GreenwoodGuy65]

Thanks for the help. I will check and see what CPUZ says.

 

I am asking because even though I have DDR400, I have to set it in the bios to 166mhz because my rig won't boot if it is set any higher with my current settings of multi 9X and fsb of 250.

[Syngensmyth]

I missed that you already had it divided with 166. that is not 166MHz it is a % of the FSB but I can't remember what %. Maybe it is 80% so should have worked. Try 150 maybe. Probably with some secondary adjustments you can run at 166. You need to give more specific spec on your ram.

 

Search the stock speed data base for your board and ram to find some secondary settings that may work.

[GreenwoodGuy65]

According to CPUZ, it is Infineon ram running at 204Mhz, so it should be DDR400 right?

 

The timings are 3,4,4,0. FSB:DRAM is CPU/11

[Syngensmyth]

Yes, sort of ... It is the "running at" that gets me. The SPD tab is not a "running at" speed (well, it is at default but does not ever change). It is the speed the bios reads on default and sets to keep from running out of spec. on a default boot. 200 SPD is 400 PC3200 ram.

 

Sorry can't find a decent pic and the laptop I am on has old pc2100 therefore no SPD that is meaningful.

 

The Memory tab shows "running at" which is a product of FSB x divider.

 

Sorry to be so nit-picky, just can't tell if you actually had it clearly.

 

Good news is you must have booted up:)

[GreenwoodGuy65]

I hope I didn't sound confused, I get that alot though

 

It is just I thought that it was strange do have CPUZ show a frequency of 209mhz when in the DRAM settings I had set it to 166, but I now know that it is not truly 166mhz, but rather a divider such as 200Mhz(1/1) option in the settings indicates.

 

All that matters is that the system is running stable at 2.2, which is more that I got just using default settings.

 

Any ideas as to why though, out of curiosity, the POST screen shows the ram as DDR333? Is it because of the divider that I set in the DRAM settings?

 

Thanks again everyone.

[3stars]

it's the divider that you have set in the bios not the actual ram speed

[Syngensmyth]

Any ideas as to why though, out of curiosity, the POST screen shows the ram as DDR333? Is it because of the divider that I set in the DRAM settings?

 

Thanks again everyone.

 

How do you have these set?

 

Genie BIOS Settings:

 

FSB Bus Frequency............................. - ???

 

DRAM Configuration Settings:

 

DRAM Frequency Set............................ - ???

[Westmassguy]

During POST, the DFI BIOS will report what the memory divider is set to, 300, 333, 360, or 400 for example, not what the memory is actually running at.

Try this for quick memory calculations:http://www.blurbdesigns.com/OcCalc/calc.htm

Memtest, and Everest will show what the actual memory speed is

[bldegle2]

166 is just one divider (based on HTT).

 

166 is aproximately 83%, when actually multiplied times the 250 HTT it comes to 207.5, pretty close way to calculate actual ram runnings.

 

150=approx 75%

 

133=approx 67%

 

180=approx 90%

 

it is just a startup divider using the HTT runnings to calculate ram speed.....

 

laterzzzz