Help! Just purchased new mem, unsure of MB.

Guys, I come to you for help.

Knowing that I needed some new mem, I just ordered for an upgrade. However, for some reason I was too stupid to actually think about this purchase a little more in-depth. I have an MSI NEO 875P LSR motherboard with (and this might be the kicker, which is why I'm worried) a Northwood P4 3.06GHz (which has a FSB of 533).

Now, what's freaking me out is that the spec page I have for my motherboard says that I /can't/ use that memory with it. What I need to know is.. is the memory I just ordered from newegg needing to be canceled asap, or am I just not going to be able to 'utilize' it at it's fastest potential? ie. if it will work at all, I'm happy with the purchase for now and will upgrade my cpu/mb later on. If it won't work at all when I put it in my system, I need to cancel the order. Anyway, any help is greatly appreciated.

-Setiri

• Supports four unbuffered DIMM of 2.5V DDR SDRAM.
• Supports up to 4GB memory size with ECC.
• Supports Dual channel DDR266/333/400MHz and up.

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I find this motherboard very stupidly done

It says that since your FBS is 533 it doesn't run DDR400 and runs DDR333 Which means that your new RAM which you just got won't run at it's stock speed but will run at 333mhz. That's not going to make the RAM bad so from what I know it should work. I'm pretty sure it will just kick back and if your going to change your mobo soon I would suggest keeping the RAM.

OK, it doesn't have to go it's full speed atm.. mostly I want it for the 2gb up from my current 1gb of ram. In the future, I'll upgrade mb/cpu/vid card (god, I don't look forward to being forced to PCI-e, I must be getting old cause I'm whining about upgrades now) and overlock it. Until then, I just want to drop it into my board and have a happy 2gb of functioning, fairly quick RAM. Thanks for your help.

PCI-E is alot better than you think Plus, if your doing all those I suggest going with AMD not intel.

Umm 533MHz FSB is just 133MHz FSB quad pumped... That memory will run happily at 133, 166 or 200MHz FSB.

I knew I should've kept that I'm not 100% sure

Firelord said:

Umm 533MHz FSB is just 133MHz FSB quad pumped... That memory will run happily at 133, 166 or 200MHz FSB.

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Not quite. The following list is a limitation with all PC3200 DDR1 memory controllers, and the Intel i865/875 series chipsets in particular:

• If your actual FSB clockspeed is 100MHz (400FSB for Intel), you can run memory at 133MHz/PC2100/DDR266 only.
• If your actual FSB clockspeed is 133MHz (533FSB for Intel) or 166MHz (there are no "667FSB" Intel CPU's), you can run memory at 133MHz/PC2100/DDR266 or 166MHz/PC2700/DDR333 only; you cannot use a 200MHz/PC3200/DDR400 memory clockspeed without risking serious stability issues.
• If your actual FSB clockspeed is 200MHz (800FSB for Intel), you can run memory at 166MHz/PC2700/DDR333 or 200MHz/PC3200/DDR400.

It's the actual FSB clockspeed that counts, in this case - and asynchronous operation with all DDR1 memory controllers is (for all practical purposes) limited to +/-PCICLK (or +/-33.3MHz) from the actual FSB clockspeed.

Thus, in the thread starter's situation, since his actual FSB clockspeed is 133MHz, he cannot run his PC3200 memory at the full 200MHz/PC3200/DDR400 clockspeed without risking system instability. Instead, he can only run his memory at 133MHz/PC2100/DDR266 or 166MHz/PC2700/DDR333. (Some BIOSes limit the maximum settable memory clockspeed to 166MHz/PC2700/DDR333 with any CPU whose actual FSB clockspeed is lower than 200MHz/"800FSB".)

The above, as I said, applies only to DDR1 (as opposed to DDR2) systems. DDR2 platforms allow asynchronous memory operation up to double the CPU's actual FSB clockspeed (this means 400MHz/PC2-6400/DDR2-800 is the maximum memory clockspeed with a 200MHz FSB/"800FSB" processor, or 500MHz/PC2-8000/DDR2-1000 with a 266MHz FSB/"1066FSB" processor, unless a lower memory clockspeed limit is imposed by the motherboard chipset or memory controller.)

i've never seen pc3200 ram not able to run at pc2700

sure, in theory, it might not work, but when you look at real world cases.... yeah

PC3200 will happily run at 100, 133, 166 or 200Mhz, it will generally run tighter timings at the lower speeds.

Thank you all so much for your help here.

Ok, so in my understanding so far, I believe that what you all are saying is that yes I can put it into that motherboard with that particular processor and it will work, although admittedly it will not operate at it's full speed due to the limitations of my CPU's FSB max of 533.

This I can be ok with until I decide to upgrade everything else in my system (which, I'm real reluctant to do as there's just not that much benefit atm.

p4 Northwood 3.06HT (currently OC'ed to 3.3)
MSI Neo 875P LSR
SB X-Fi Platinum (what a WONDERFUL card btw.. my old Audigy 2 was one of the many that had that lockup and SCREAM feedback at you on radom occasion problems)
Antec TrueBlue
Radeon 9800Pro

So.. yeah. It just doesn't make sense to essentially throw out my chip, mb and 9800Pro right now. Without wanting to spend more than $500 at a time, what could I possibly get that would be such a noticeable impact on my typical gaming/computer use situations? A n 800 FSB 3.2? The only thing that would be that much more noticeable is a new vid card and honestly, I can't justify buying another AGP since that's almost done with.. but I can't go buy a new PCI-e without a new chip and mb. I'm stuck, and I have a feeling a lot of others are at this same spot. Thanks again so much for all the help.

there's a simple solution to this issue.. overclock

Firelord said:

PC3200 will happily run at 100, 133, 166 or 200Mhz, it will generally run tighter timings at the lower speeds.

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That's only for the memory. But what I've said in my post above actually takes chipset/memory controller limitations into account.