Overclock with RAMBUS

Hello people, I have a P4 2.4 with an ASUS P4T533 and 2 Sammung 800 mhz RIMM modules.
I want to overclock it but i don't know if my memory will be stable or not.

Thanx

I've had two RDRAM systems (RIMM or rambus which means the same). I had Abit TH7-II mobos, but I think the Asus has similar BIOS choices for memory settings. The answer is yes you can overclock it.

Most Samsung PC800 will handle close to 1000 MHz. Lots of people have gotten PC1066 performance out of Sammy PC800. You can always set the memory to 3X instead of the default 4X. By the way... is this a 2.4A or 2.4B CPU?

Not from my personal experience, just from what I have heard, but I hear rambus oc's like garbage.

I was running a rambus setup up until I ****ched here shortly ago, I don't agree at all that it dosn't OC well, You just need good ram is all. Not a plug by any means, but I Do have 2x256 pc1066 Mushkin rdram sitting here, that is about 2 weeks old, if anyone is interested.

I agree that RDRAM systems don't overclock quite as well as DDR systems (on average), but until just this last spring with the new dual channel DDR, RDRAM was still whoopin' butt on DDR as far as memory bandwidth goes. Don't expect super high FSB with RDRAM systems, but with the right CPU, you can still make them sing.

I've got an Abit TH7II-R & P4-1.6A with 512MB of Samsung PC800 (2x256sticks) running at FSB140 which is equal to PC1120 speeds. I've been running at this speed for MONTHS! It might not o/c as well as the latest DDR, but SiSoft Sandra Mem benchmarks are right near the 3500 mark, which is some pretty awesome bandwidth for obsolete memory, IMO. - Dave

Batboy, it's a 2.4B (533mhz bus) I've heard that it's easy to overclock it, so I'm going to buy some fan's for the box and probably I will push it to 2.8 or 3.0 without watercooling (I hope so)
Also I have a Zalman 6500 Cu

For a B (133Mhz FSB) chip I'd get PC1066 RDRAM to match at least the stock speed of that chip. Synchronous operation is a big plus in this case. From there, you can try to milk some more performance out of your setup. Either by using x4 (sync) settings, in which case you should be able to get about 155Mhz FSB, or using relaxed x3 (async as you have now) ram timing settings, where I'd expect 170~180Mhz FSB if your chip & board can take it. That last thing may be an issue depending on what serial your P4T533 carries though.

Thanx.
I'm trying to find 1066 memory but it's really expensive, so I'm not sure if I will buy it or not because now I have 512 Mb of 800 memory and, if I change, I have to buy 1024 of 1066, which will cost about 300 € or more.

Ok, I think your first goal should be 2.7 gig, that's 150 FSB using the 3X memory multiplier to give you 150X4X2=900 MHz memory speed. Your CPU, motherboard, and RAM should all do that without too much problem. Beyond that is up to the components, but certainly 160 FSB could be within reach. Don't forget to set the PCI/AGP bus to default speed before trying to overclock.

FIZZ3 said that FSB on my P4T533 depends on it's serial, ¿is there any place where i can find the max FSB for my serial?

Generally it's trial and error to find the max speed for your system. I've never had that motherboard, so I don't know what it'll do. Also, I'm not entirely sure what Fizz3 meant by the serial thing. But, he's a respected long term member who knows his stuff. Perhaps you should PM or email him for more info.

I'm sorry I should have been more clear.

There were problems with the P4T533 series mainboards. The initial batch of boards, carrying serial number 27xxx would often be unstable at even stock 133Mhz FSB.
Later boards remained "unrevised" -at least offcially, and continued to be of the 1.03 revision. However, the serial numbers of the newer boards did change. Very tellingly, there were last-minute modifications made to these boards, visible to the naked eye. One of these was a resistor soldered to the back of the board near the memory slots, another was the addition of a fan to the northbridge heatsink.
The point of all this is that you could have a problematic board, without really knowing it yet, and then get stuck while you are trying to OC. I've had that experience too, so it is with great empathy that I can tell you it sucks.
So what I'd recommend is checking your serial number beforehand (it can be found on a sticker on the box, very conveniently) and exchange the board if it carries the 27xxx serial, where xxx is any digit or letter, and it exhibits stability problems. 28xxx, 2Bxxx, 2Axxx and other serials are supposed to be OK. If the serial seems fine (and/or you can locate the 'mods' I talked about), and the board is at least stable at stock, then have fun overclocking.

BTW Batboy was right in that there is no fixed max frequency for any serial; it will still be trial and error, but knowing the suspect numbers may at least prevent headaches later on.

What FIZZ3 said is right, and assuming you have a good P4T533, the overclock on the RIMM4200 was all over the place. If you are lucky and got good sticks, they max out around 155-158/4x, which is good for around 200/3x.

Not from my personal experience, just from what I have heard, but I hear rambus oc's like garbage.

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Heh heh. I've done 180/3x on a TH7II with PC800-40, CPU limited. Unbuffered bandwidth was 2400+. I have tested half a dozen 865 Springdale and 875 Canterwood boards, and if you are stuck at 5:4, CAS 2.5, I've seen unbuffered bandwidth in the 2400 area. And these rigs were running 3.2+ gig, 250+ fsb, dual channel.

Clevor said:

Heh heh. I've done 180/3x on a TH7II with PC800-40, CPU limited. Unbuffered bandwidth was 2400+. I have tested half a dozen 865 Springdale and 875 Canterwood boards, and if you are stuck at 5:4, CAS 2.5, I've seen unbuffered bandwidth in the 2400 area. And these rigs were running 3.2+ gig, 250+ fsb, dual channel.

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I've always been somewhat surprised to see how feisty those TH7-II boards were. They were based on the 'older' 850 (non -E) chipset, but were still able to pull impressive speeds... often even with vintage PC800 ram. Very nice, altough a pity at the same time when you realize Abit didn't follow up on it with an 850E board. Ah well.

well, I have two sticks of PC800 Samsung RDRAM, 64mb each. I have them in my dual P2 400mhz..and overclocked it to 912mhz.. So this is good ram..and I bought it used!