PC2-4200?

[scsgoal31]

Can someone quickly run a program such as cpuz from www.cpuid.com or something similar and let me know what the memory FSB is for a system with PC2-4200 RAM?

Mine reads at 100MHz (400 MHz net), and I really don't think that's right. That would be PC2-3200, and I'm going to be pretty upset if thats what they sent me.


Argh, PC Wizard 2006 also says its bandwidth is 3200 GB/s which is obviously PC2-3200.


*edit*

Is it because the processer is only 400MHz FSB? I still didn't think memory would clock down, you would just have a Mem:FSB ratio that wasn't 1:1


*Further EDIT*

Just ignore me...it's the chipset in the z60 that limits the DDR speeds. I wonder why Lenovo doesn't just sell it with PC2-3200 then, since thats as fast as it can run.

[christopher_wolf]

Just ignore me...it's the chipset in the z60 that limits the DDR speeds. I wonder why Lenovo doesn't just sell it with PC2-3200 then, since thats as fast as it can run.

Where did you hear that? The T43 and the Z60 share the same tpe of memory and I don't think the Z Series has them bandwidth limited.

[invictus]

Just ignore me...it's the chipset in the z60 that limits the DDR speeds. I wonder why Lenovo doesn't just sell it with PC2-3200 then, since thats as fast as it can run.

Where did you hear that? The T43 and the Z60 share the same tpe of memory and I don't think the Z Series has them bandwidth limited.

FWIW - My Z60m (2529-EAU) has 1GB of PC2-4300 RAM and it shows at 133MHz but then also my FSB is 533MHz...

- Jon

[smek]

Chipset allows 533, its the chip that limits it, and seeing as you have a 400 bus chip it will drop the memory to the same speed. If you want to change that you can either buy a P-M or perform a pin-mod on that Celeron to bring it to a 533 bus.

[scsgoal31]

This is still really bothering me..here's a topic I posted at another forum for help...it introduces a new question as well.

I have a Celeron - M with a 400Mhz FSB.


I also have 2x512MB of PC2-4200 DDR RAM. (PC2-4200 = DDR533)

Now, my laptop is running the memory at only 400MHz, I assume to make it a 1:1 ratio with the processor. I ask, why? Would a 3:4 ratio be bad? I'm certainly not given the option in my BIOS...is there any other way to force the memory to run at the full 533MHz?


Secondly, CPUZ confirms that I am running in dual channeled mode.

However, PC Wizard 2006 states I only have a bandwidt of 3200 MB/s.

PC2-4200 in dual channeled mode should be 8400 MB/s, correct?

Even if I assume since it's only running at 400 MHz, that its really just PC2-3200. Then shouldn't it at least be at 6400 MB/s?

Any help would be greatly appreciated as I'm very frustrated!

[medevilenemy]

The FSB speed and RAM bandwidth/speed are two different things. The FSB determines, to a degree, how fast the processor can communicate with memory... but there are other factors involved. Memory speed (effective) is also determined by the avaliable bandwidth/speed of the physical memory itself, and the bandwidth/speed of the physical chipset and ports which connect the memory with the system. If your chipset is not physically capable of supporting the speed of your RAM it will either not function or the RAM will be forced to run slower. Also, if your chipset has been clocked down (either by you or the OEM/provider/etc) below the speed of the RAM, it will run slower.

Another thing to note is that PC2-4200 DOES NOT RUN AT 533 MHZ (also, PC2-4200 is known as DDR2-533, not DDR-533). It is actually 266Mhz Double-Pumped. The effective speed of 533 Mhz memory would actually be 1066Mhz (Double Pumped). (i know, silly distinction... but it should be note)

Thirdly, it is pointless to get RAM that operates faster than your FSB can handle; since it will be clocked down, buffered (in the on-die cache), and will cause a memory bottleneck. Memory interfaces work best when all components are capable of running at the same speeds. It is, however, ok to have an FSB that is too fast for the memory, since it will simply slow itself down to handle the RAM. There will be no bottlenecking in this instance.

And PC Wizard isnt measuring the actual specified or operative speed of the interface, instead it measures the effective speed. That is, the speed of the interface after it is acted upon by all factors.

I probably just ranted nonsense.... oy.