Asus AV8 and 2Gb RAM ...Frequency Drop

[cptwhite_uk]

I've just purchased myself 1Gb of Dabs Value RAM (£54 delivered, CAS 2.5 PC3200)

The sticks weren't matched but I'm running them in duel channel.

They're an addition to my 1Gb of Corsair VS PC3200

When referring to CPU-Z with either set, The frequency is at 200 as it should be, but when I stick both sets in (Corsair in banks 1 & 3) The frequency of the RAM drops to about 153.

I'm pretty new to RAM and the business of running things Async to the HTT speed etc but I think I've read this is a problem with my board (or all 939 boards?) when using + 1Gb in twin duel setup.

Does anyone know of a solution, a manual setting in the BIOS which will allow me to specify and fix the RAM frequency to 400DDR?

I've had a play around with a value which you could set to Auto or Limit at the Top of the Memory settings. But the 'limit' option is just an upper limit 333DDR, 400DDR etc from my best guess and not a fixed speed at which to tell the RAM to run. I can't find any other entry which might solve this.

Any help appreciated.

Sorry CPU is an Athlon 64 3500+

and before anyone asks, I'm doing large scale graphics work that's why I need 2Gb! It's not going to affect my work, but I'm worried about a drop in the performance of my games.

Finally when using the Dab Value stuff CPU-Z rates it at CAS 3.0 at 200Mhz ....have I been ripped off since it was advertised as 2.5 @ PC3200 - setting in BIOS at set to auto for RAM timings.

[Rave]

Right, several thingsa to answer here:

I've just purchased myself 1Gb of Dabs Value RAM (£54 delivered, CAS 2.5 PC3200)

The sticks weren't matched but I'm running them in duel channel.

That's fine, 'matched pairs' are just a sales gimmick, it means nothing.

When referring to CPU-Z with either set, The frequency is at 200 as it should be, but when I stick both sets in (Corsair in banks 1 & 3) The frequency of the RAM drops to about 153.

I'm pretty new to RAM and the business of running things Async to the HTT speed etc but I think I've read this is a problem with my board (or all 939 boards?) when using + 1Gb in twin duel setup.

Well, the problem is with using 4 double sided DIMMS with an Athlon 64. It's basically impossible to sync them up at 200MHz, so the memory controller on the processor defaults to a lower speed. You may be able to force it to run at 200MHz albeit with a 2T command rate, but even this may be beyond your processor. Apparently Newcastles are slightly better than Winchesters in this regard.

Basically, if you want to run 2GB of RAM at 200MHz or more you need 1GB sticks- obviously that puts the price up considerably.

and before anyone asks, I'm doing large scale graphics work that's why I need 2Gb! It's not going to affect my work, but I'm worried about a drop in the performance of my games.

Well, you'll probably get a performance drop from running your RAM at 166MHz instead of 200, but it's only likely to be a couple of frames per second.

Finally when using the Dab Value stuff CPU-Z rates it at CAS 3.0 at 200Mhz ....have I been ripped off since it was advertised as 2.5 @ PC3200 - setting in BIOS at set to auto for RAM timings.

SPD timings don't always get recognised properly; obviously if the Corsair is CAS 3 then the board will default all the modules to the slowest speed. You could set the DABS modules to 2.5-3-3-7 manually and make sure they pass memtest and Prime95, if so it doesn't really matter what they default to.

[cptwhite_uk]

Thanks for the quick reply RAVE. Forgot to mention the Dabs RAM is 1 sided. Only the Corsair is double sided.

[Rave]

Hmm....O.K. then, that increases your chance of success somewhat. Let me go and find a bios screeny for the board.

Edit: I take it this is an Asus A8V?

Edit: assuming it is, there are some bios screenies here:

http://www.ocworkbench.com/2004/asus/a8vdeluxe/g3.htm

What I would do to find the maximum stable memory clock is (if possible) set the multiplier of the cpu to 9 (instead of 11). Set the HT multiplier to 3X. Then in the memory screen set the memclock mode to async with the memory running at 166MHz. Set the command rate to 2T and timing to 2.5-3-3-11 (or slacker if you like, but there's not much point in that).

Then save, restart, boot your OS, and then use Clockgen to increase the FSB a bit at a time. If you have Prime95 torture test running in blend mode in the background you should find the point where the memory craps out. Once that's done you can work out the settings that get the memory running at their fastest stable speed while keeping everything else stock (or at your previous OC).

[cptwhite_uk]

Hmm....O.K. then, that increases your chance of success somewhat. Let me go and find a bios screeny for the board.

Edit: I take it this is an Asus A8V?

Indeed Asus A8V Deluxe WiFi Edition...sorry about the delay just ran 3Dmark 2003 - about 500 point drop - 12,500 ish to 12,000 - i'm not going to worry about that

Just going to collect a Pizza I'll have a play when I'm done!

[HKPolice]

Running 4 sticks = automatically forced divider. No other way to get around this unless you try OCing the HTT.

[StormPC]

Matched pairs are not a gimmick. They are often not any better for overclocking than unmatched pairs but you have a better chance of a higher overclock. It's like the difference between a 3000+ Winny and a 3500+. The 3000+ could overclock higher than the 3500+ but the odds are better with the 3500+.

Sell all of that RAM and get a couple of 1GB sticks. You'll be happy you did. It's not worth it to have to worry about whether or not your system is stable, especially when you're having to run low speeds with crap timings. A64s need to run at 200MHz (DDR400) plus.

Pizza is good!

[oralpain]

Some motherboards will allow you to use the 200Mhz ratio, but you will need T2 with 4 stick regardless.

I concur that you would be better off with two 1 GB dimms.

You could just lower the CPU multiplier, HT ratio, keep the DDR333 ratio, and up the refernce clock to around 240Mhz.