Will this RAM work?

Hello All,

I'm going to be upgrading my CPU, motherboard and RAM soon, but had a quick question.

I'm running on a MSI 845 Ultra-AR board with 768MB of PC2100 RAM. With the upgrade I'm going to do, I'll be purchasing PC3200 RAM to use.

I'd like to get a little boost in performance with this board right now (a slight oc), if possible, before I upgrade in 3-5 months from now. So I was thinking of getting the RAM now and using it in this board.

Anyone know if PC3200 RAM will run in this board, and if so, there's no risk of ruining the PC3200 RAM is there? Thanks.

There can be only one.
6 answers Last reply
More about will work
  1. 1GB is optimal.

    Doesnt seem like you can do anything outstanding on this board.

    I would upgrade to a better board before spending more money on an expensive memory upgrade.

    But if you must, another 256MB would be all you would need.
  2. The only problem I see is with the 845 chipset. You need to make sure whatever memory you get is single sided. The 845 chipset has a banking limitation which requires you to use all single sided modules or one double sided module in slot one and two single sided modules in slots two and three. So be careful what memory you get.

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  3. Also keep in mind that your board is 100MHZ FSB. PC-3200 (DDR-400) requires 200MHZ bus.

    You might want to stick with PC-2100 (DDR-266) for now. DDR-266 needs a 133MHZ bus, which is a closer match to your FSB.

    You might be able to overclock your board. But I think 200MHZ might be too much for your board. Check it out in your system BIOS. Though if you increase the FSB too much, your system might not boot. In this case you will need to pull the CMOS jumper pin to reset your BIOS.

    Also, what CPU are you using?
  4. No. The best single-channel solution for a 100MHz bus P4 is 200MHz RAM (DDR400). That's because with the QDR CPU bus has a bandwidth match to DDR SDRAM that's twice as fast.

    But his chipset doesn't support a 2:1 RAM:CPU clock ratio, so he can't get DDR400 to run at full speed. If it were an SiS 645 chipset board with that ratio enabled (such as the P4S533), he could do it (against recommendations of the hardware vender). I have.

    I believe the fastest ratio the 845 supports is RAM:CPU of 5:3, DDR333 with the 400 bus CPU. As long as there are no BIOS bugs, his board would be able to run DDR400 at the highest supported ratio of the chipset. And assuming I'm right about the 5:3 ratio being available, that means his 200MHz DDR400 would run at 166MHz, DDR333.

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  5. Thank you all very much for your replies. My apologies for not providing enough information as well, so here's a bit mroe detail.

    The CPU I have is a P4 1.8GHz 400MHz FSB. There are 3 RAM slots on this board. The CPU Ratio Selection is locked in the BIOS, and I can't seem to find if it can be unlocked or not. The CPU FSB clock however, is adjustable from 100-200MHz in incrememts of 1MHz.

    DRAM Frequencies are adjustable to either Auto, 200MHz or 266MHz.

    The 845 chipset can handle only 4 memory banks of memory. So, you can run 2 sticks of double sided memory (4 banks) in two slots, or, 3 sticks, where one is double sided and the other two are single sided, up to a maximum of 2GB of memory. Bottom line is to make sure the combination of 1-3 modules doesn't exceed 4 memory banks.

    Currently, I'm using one double sided stick of Crucial 512MB PC2100 (mem slot 1) and one double sided stick of Crucial 256MB PC2100 (mem slot 2).

    What I was asking on these forums was whether you think there'd be any performance boost, meaning would it be worth it now, for me to remove ALL of the RAM I'm currently running, and replace it with the 1GB PC3200 RAM (2 sticks of double sided RAM) that I will be using with my new PCI-E motherboard and processor? Higher speed RAM would allow me to OC a bit, plus it's an addtional 256MB of RAM over what I'm using now. I know I won't be able to run the PC3200 RAM at it's fullest speed, that's a given with the limitations of this board.

    I did have a brief chat with an online Crucial memory rep, and they did say that PC3200 RAM would work, but they didn't recommend it because it could potentially encounter instability issues. I have no idea why, but that's what they said.

    If it's not worth the trouble, that's fine, just thought I'd at least ask.

    There can be only one.
  6. If you change your RAM from Auto to 200 you can overclock with what you have. If that's a Northwood P4 (512k cache), you can most likely get it to 2.4GHz at 133MHz FSB (200 RAM setting becomes 266 again from overclocking). You have 768MB of RAM, I'd leave the system alone for parts, try overclocking it, and work on building a new system later when you can afford to do the whole thing.

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    <font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
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