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Best DDR2 for E6420

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April 28, 2007 2:07:25 AM

Hello :) 

After seeing some topics around here... Im still not clear about, what the best memory settings for a core duo are...

I mean, I see talking about 1:1 (have no idea what that is), things like 5-5-5-5-12, 4-4-4-4-10 (or whatever, still in the blue).
And also about FSB speed, but I see you mention 533 Mhz and stuff like that, but never 1066 which I think is what is for Core Duos or new ones...

So... I was hoping someone could lend me a hand or give me a link to understand this...
I've been here
http://www.xbitlabs.com/articles/memory/display/core2du...

But like I said before they still talk about 5-5-5-5-12, or FSB of 266 Mhz (when in the tech details for processors it says its 1066!).

So, I have these scenarios

1. Stock E6420, Stock DDR2 modules (2 GB)
2. Overclocked E6420, Stock DDR2 modules (2 GB)
3. Stock E6420, Overclocked DDR2 modules (2 GB)
4. Overclocked E6420, Overclocked DDR2 modules (2 GB)

About CPU OC'ing... I wanna make it n00bish. That is I WONT buy non-stock coolers or water cooling or super ultra 2000 cooler $3 billion US... since Ive been told before in my previous posts I can try to overclock it reasonably leaving my stock heatsink and all, that's what Im doing ;)  Not any step further.
From what I saw in that article, if I wanna go slow (this is me making conclusions), I have to raise the multiplier a little bit..
So [whatever the frequency is] * little higher multiplier = higher Ghz speed that the stock one.
I think thats about it, aint it?
On why they keep saying 266Mhz*7 for instance and NOT 1066Mhz*7, where 1066Mhz is the FSB as advertised in the CPU specs, beats me.

On memory overclocking, I guess you dont call it overclocking but rather ratio adjustment? (1:1, 1:2, 34:67?)
Maybe it also has to do with those 5-5-5-5-16, 4-4-4-4-12 numbers, either way I dont understand either :?

So... you have 4 scenarios... if its basically the same for the OC'ed CPU, and it just depends on the DDR2 adjustment, then I guess it makes them just 2 scenarios.

What Im asking is what DDR2 speed (533, 667, 800?) and I guess ratio and numbers (5-5-5-5-12), though Ill figure those out later.

Its just I was thinking of getting Kingston ValueRAM 667 as advised in a previous topic (since that seems to be a good speed for the E6420), but after seeing so much topics Im confused (how weird! :lol: )

Thanks for your time :) 

More about : ddr2 e6420

April 28, 2007 2:24:27 AM

Quote:
Hello :) 

After seeing some topics around here... Im still not clear about, what the best memory settings for a core duo are...

I mean, I see talking about 1:1 (have no idea what that is), things like 5-5-5-5-12, 4-4-4-4-10 (or whatever, still in the blue).
And also about FSB speed, but I see you mention 533 Mhz and stuff like that, but never 1066 which I think is what is for Core Duos or new ones...

So... I was hoping someone could lend me a hand or give me a link to understand this...
I've been here
http://www.xbitlabs.com/articles/memory/display/core2du...

But like I said before they still talk about 5-5-5-5-12, or FSB of 266 Mhz (when in the tech details for processors it says its 1066!).

So, I have these scenarios

1. Stock E6420, Stock DDR2 modules (2 GB)
2. Overclocked E6420, Stock DDR2 modules (2 GB)
3. Stock E6420, Overclocked DDR2 modules (2 GB)
4. Overclocked E6420, Overclocked DDR2 modules (2 GB)

About CPU OC'ing... I wanna make it n00bish. That is I WONT buy non-stock coolers or water cooling or super ultra 2000 cooler $3 billion US... since Ive been told before in my previous posts I can try to overclock it reasonably leaving my stock heatsink and all, that's what Im doing ;)  Not any step further.
From what I saw in that article, if I wanna go slow (this is me making conclusions), I have to raise the multiplier a little bit..
So [whatever the frequency is] * little higher multiplier = higher Ghz speed that the stock one.
I think thats about it, aint it?
On why they keep saying 266Mhz*7 for instance and NOT 1066Mhz*7, where 1066Mhz is the FSB as advertised in the CPU specs, beats me.

On memory overclocking, I guess you dont call it overclocking but rather ratio adjustment? (1:1, 1:2, 34:67?)
Maybe it also has to do with those 5-5-5-5-16, 4-4-4-4-12 numbers, either way I dont understand either :?

So... you have 4 scenarios... if its basically the same for the OC'ed CPU, and it just depends on the DDR2 adjustment, then I guess it makes them just 2 scenarios.

What Im asking is what DDR2 speed (533, 667, 800?) and I guess ratio and numbers (5-5-5-5-12), though Ill figure those out later.

Its just I was thinking of getting Kingston ValueRAM 667 as advised in a previous topic (since that seems to be a good speed for the E6420), but after seeing so much topics Im confused (how weird! :lol: )

Thanks for your time :) 


In Core 2 Duo's the ratio of the memory to the CPU clock is not really that important, as it does not affect performance that much. If I were you, I would get some ddr2 800 ram and OC your E6420 to 3.2 Ghz, which is 400 X 8 = 3.2 Ghz, which is at 1:1 ratio with your memory and should yield the best performance. The 1066 represents the processor's fsb, or front side bus. It has 8 X 266 because 8 is the multiplier, and 266 is the clock for the processor. It is too complicated to get into so I'll let Jack handle this part :p 
April 28, 2007 3:18:12 AM

You are getting yourself quite confuzzled with all that mumbo jumbo. Here is what you need to know: link.

You can see that no matter what you buy for memory you will get good performance. Frequency matters more; timing matters less, but in the end it makes very little difference.

A good reason to get after-market coolers is that they are quieter than the stock ones. This is why I get them.

For overclocking, you need memory that can take a high frequency, and a CPU with a low "Natural" FSB frequency, like the E4300 (It has 200 MHz FSB instead of 266 MHz FSB that the E6420 has). You also need a motherboard that acommodates high FSB frequency. At this point you increase the FSB as high as it will go (You do this by changing BIOS settings). The CPU multiplier stays the same, so the effective clock speed increases.

For example, if you took an E4300 (FSB=200 MHz, Multiplier=x9, stock clock=1.8GHz) and increased the FSB through motherboard settings to 300MHz, you would have overclocked your E4300 to 2.7GHz.

Understanding "The Limits"
There is a limit to how high the FSB can go. This limit is determined by:
A) Your motherboard
B) Your memory
You can check motherboard and memory reviews for how high they got the FSB. For memory, you are looking for "Memory Clock" (e.g. 1000MHz) and divide by 2. The reason for this is memory these days is "Double Data Rate" (DDR) memory. It "Fires" twice for every FSB clock.

Memory clock speed = FSB clock speed x 2.

So a memory a reviewer OCed to 1000MHz would be able to accommodate any FSB 500 MHz or lower. Memory samples are different; you might not be able to OC the same module as high as a reviewer did.

Motherboard: They will usually tell you in reviews exactly how high they got the FSB.

As you approach the FSB limit for the "Limiting" component of your system (Either RAM or motherboard), your system will become unstable. You can only go as fast (In terms of FSB) as your RAM and motherboard will allow.

There is a limit to how high (processor) clock speed can go. This limit is determined by
A) Your CPU ONLY
To get CPU clock speed you use the following formula:

CPU Clock Speed = FSB Clock Speed x CPU Multiplier.

As you approach the clock speed limit for your processor, your system will become unstable. You can only go as fast (In terms of CPU clock speed) as your CPU will allow.

So how in the world did they get 1066 FSB? It turns out that the Intel CPUs are "Quad-pumped" meaning instead of once or twice, they can issue commands to the north bridge four times per FSB clock.

They report it like this:
CPU "Marketed FSB Speed" = "Real" FSB Clock Speed x 4

Overcoming the limits
So like I said before as you approach limits your system will become unstable. You can try to stabilize an unstable system by increasing CPU and RAM voltages. (I am not sure about motherboards. From what I understand, motherboards are limited in FSB by things other than voltage. Usually increasing motherboard voltages will not help.)

I need to tell you about memory timing: In a nutshell, memory will still work (Become more stable) at higher frequencies if you relax the timing. That is make the timing numbers bigger. When you set the timings you are telling the North Bridge memory controller how to control the memory. By setting tight (short) timings you are being "Agressive" and by setting loose (long) timings you are being "Conservative." Better memory will accommodate tighter timings at higher frequencies. Like I said before, timing does not really matter - You will get good performance no matter what the timing is.

If you have more questions please post them.
Related resources
April 28, 2007 4:58:20 AM

Quote:
In Core 2 Duo's the ratio of the memory to the CPU clock is not really that important, as it does not affect performance that much. If I were you, I would get some ddr2 800 ram and OC your E6420 to 3.2 Ghz, which is 400 X 8 = 3.2 Ghz, which is at 1:1 ratio with your memory and should yield the best performance. The 1066 represents the processor's fsb, or front side bus. It has 8 X 266 because 8 is the multiplier, and 266 is the clock for the processor. It is too complicated to get into so I'll let Jack handle this part :p 

Oh thanks :)  And who's jack? If that's the guy below then indeed he's like Kingston's engineer or something :p 

Quote:
You are getting yourself quite confuzzled with all that mumbo jumbo. Here is what you need to know: link.

Great link. Explains a lot thanks :) 

Quote:

For example, if you took an E4300 (FSB=200 MHz, Multiplier=x9, stock clock=1.8GHz) and increased the FSB through motherboard settings to 300MHz, you would have overclocked your E4300 to 2.7GHz.

Great :D  So it seems to be easy as 1-2-3, just that I have to take care of stability and the like.

Ok so now lets do some math to see if I got it right.
For overclocking I think Ill make some maths later when I have some time, or once I get all the parts and have assembled my PC.

Quote:
For memory, you are looking for "Memory Clock" (e.g. 1000MHz) and divide by 2. The reason for this is memory these days is "Double Data Rate" (DDR) memory. It "Fires" twice for every FSB clock.

ValueRAM 2GB Kit UNB 533MHz 240-Pin ( KVR533D2N4K2/2G )

Since the only "Mhz" I see are the 533 and nothing else in the kingston site's item specs, I take it as the memory clock is that.

So...
Memory Clock = 533/2 = 266.5 Mhz (dont know if these are to be rounded!)

Quote:
Memory clock speed = FSB clock speed x 2.

I take this as you mean THIS IS what my RAM MHz should be for best performance.
So...

Intel Core 2 Duo processor E6420 (1.86 GHz 4 MB L2 cache)
(What is weird is that this is amazon -where Im forced to get these from- and in newegg its 2.13GHz :? But weird enough they have the same model number BX80557E6420SLA4T? I think either amazon is screwed on their specs or there is something fishy!!! :roll:) 

Quote:
So how in the world did they get 1066 FSB? It turns out that the Intel CPUs are "Quad-pumped" meaning instead of once or twice, they can issue commands to the north bridge four times per FSB clock.

They report it like this:
CPU "Marketed FSB Speed" = "Real" FSB Clock Speed x 4


FSB Clock Speed = 1066/4 = 266.5 MHz

Now...

Quote:
Memory clock speed = FSB clock speed x 2.

Well its pretty obvious the math here was very 1-2-3 as I took what seems to be the "perfect" companion to the FSB (aka X/2*2 = X!!! :lol: )

"Ideal" Memory clock speed = 266.5 x 2 = 533 MHz

"Real" clock speed = 533 MHz
Yahoo!!! Seems like its ideal to have that memory frequency right?

Now:

Quote:
There is a limit to how high (processor) clock speed can go. This limit is determined by
A) Your CPU ONLY
To get CPU clock speed you use the following formula:

CPU Clock Speed = FSB Clock Speed x CPU Multiplier.


"Maximum" CPU Clock Speed = 266.5 x CPU Multiplier

Im sorry :( 
I dont know where to find the multiplier... its not on Intel site specs for the E6420 neither in the specs for the mobo (GA-965P-DS3)
Can I only now when I have the thing and checking the BIOS then? :?

Quote:
I need to tell you about memory timing: In a nutshell, memory will still work (Become more stable) at higher frequencies if you relax the timing. That is make the timing numbers bigger. When you set the timings you are telling the North Bridge memory controller how to control the memory. By setting tight (short) timings you are being "Agressive" and by setting loose (long) timings you are being "Conservative." Better memory will accommodate tighter timings at higher frequencies. Like I said before, timing does not really matter - You will get good performance no matter what the timing is.

Im taking this, as there are no formulas for timing... rather just trial-and-error approaches by fiddling with the parameters in the BIOS then? Since you say it doesnt really matter then Im not concerned :p 
BUT... I take it as I can only know the available timings for my memory once its installed and I get to the BIOS? Or are they BIOS-biased :lol:  or maybe just hidden till you install the thing.

One last thing that isnt 100% clear is the rate... Lets say what is 1:1? :?
Is it

Quote:

Memory clock speed = FSB clock speed x 2


That's 1:1? And then 1:2 would be

Memory clock speed = FSB clock speed x 4?

Thanks a lot for your time :) 
April 28, 2007 6:25:47 AM

1:1 ratio means that the memory frequency and the cpu clock are running at the same speed...example:

533 memory - 266 mhz
1066/4 - 266 mhz

they're both the same, so they run at 1:1 ratio. If you got ddr2-800 memory, which runs at 400 frequency, you would have to overclock your cpu to 400 mhz clock to achieve 1:1

So lets say you got some 533 memory, it would be at a 1:1 ratio when the cpu is at stock speed because 533/2 - 266 mhz and the cpu is running at 266 X 8 = 2.13 ghz...

You don't need to worry about the multiplier, as most core 2 duo cpus' multipliers are locked (except the x6800, qx6700, and qx6800). If you want to overclock, like I said, just get some ddr2-800 ram and raise your cpu clock to 400 mhz. Or you can get some 667 ram, and oc your cpu clock to 333 mhz. Your cpu has a multiplier of 8 btw. Make sure you overclock around 5-10 mhz at a time to check for stability. And it helps to get a better fan/heatsink for the cpu.

Timings should be somewhere in the bios, but they are also on the site you buy it from (or should be). They just represent how fast the memory reacts to certain things, retrieve things, find stuff, etc...
April 28, 2007 3:00:56 PM

Quote:
Yahoo!!! Seems like its ideal to have that memory frequency right?
I don't know about "Ideal." 533 MHz memory is the minimum you need to run with a 266 MHz FSB. Increasing memory clock will increase performance, but not very much (See the link I provided earlier). Because Intel systems have their memory controller in the north bridge, you can change the memory clock speed independently of the FSB. (On AMD systems you cannot do this because the memory controller is inside the processor, and therefore must be synchronized to the FSB).

I'm not exactly sure why increasing memory clock will increase performance. Some people say synchronizing FSB and memory clocks will provide a slight performance boost. I'm not sure about this. Certainly a 1000 MHz memory will perform better than a 533 Mhz, but I'm not sure if a 667 MHz memory will because of the supposed "1:1 Boost."
Quote:
Im sorry :( 
I dont know where to find the multiplier... its not on Intel site specs for the E6420 neither in the specs for the mobo (GA-965P-DS3)
Can I only now when I have the thing and checking the BIOS then? :?
Check your BIOS. It IS specified by intel, check retailers websites. You could also check your BIOS, "System monitor" section which tells you clock speeds, timings, voltages, and fan speeds.
Quote:
One last thing that isnt 100% clear is the rate... Lets say what is 1:1? :?
It is a ratio. The number on the right is "Real" FSB speed. The number on the left is "Real" memory clock speed.
CPU = E6420 = 266 MHz "Real" FSB
Ram = (Any 533 MHz module) = 266 MHz "Real" memory clock (Vendors report twice this number because they are double-data rate modules)
CPU FSB (266 MHz) / Memory Clock (266 MHz) = 1, so your ratio is one to one.
If you increase the memory clock to say, 533 MHz (1066 DDR), then your ratio is:
533/266 or 2:1 ratio.
April 28, 2007 5:30:44 PM

Quote:
Yahoo!!! Seems like its ideal to have that memory frequency right?
I don't know about "Ideal." 533 MHz memory is the minimum you need to run with a 266 MHz FSB. Increasing memory clock will increase performance, but not very much (See the link I provided earlier). Because Intel systems have their memory controller in the north bridge, you can change the memory clock speed independently of the FSB. (On AMD systems you cannot do this because the memory controller is inside the processor, and therefore must be synchronized to the FSB).

I'm not exactly sure why increasing memory clock will increase performance. Some people say synchronizing FSB and memory clocks will provide a slight performance boost. I'm not sure about this. Certainly a 1000 MHz memory will perform better than a 533 Mhz, but I'm not sure if a 667 MHz memory will because of the supposed "1:1 Boost."
Quote:
Im sorry :( 
I dont know where to find the multiplier... its not on Intel site specs for the E6420 neither in the specs for the mobo (GA-965P-DS3)
Can I only now when I have the thing and checking the BIOS then? :?
Check your BIOS. It IS specified by intel, check retailers websites. You could also check your BIOS, "System monitor" section which tells you clock speeds, timings, voltages, and fan speeds.
Quote:
One last thing that isnt 100% clear is the rate... Lets say what is 1:1? :?
It is a ratio. The number on the right is "Real" FSB speed. The number on the left is "Real" memory clock speed.
CPU = E6420 = 266 MHz "Real" FSB
Ram = (Any 533 MHz module) = 266 MHz "Real" memory clock (Vendors report twice this number because they are double-data rate modules)
CPU FSB (266 MHz) / Memory Clock (266 MHz) = 1, so your ratio is one to one.
If you increase the memory clock to say, 533 MHz (1066 DDR), then your ratio is:
533/266 or 2:1 ratio.

The 1:1 ratio for Core 2 Duo's doesn't really do much, it's the higher frequency that plays a part in it, and still the performance isn't very noticeable. I would stick with ddr2-800 just because it'll last you for a good amount of time, and they're getting very cheap.
April 28, 2007 8:54:42 PM

Thanks guys, you are really helpful :) 

OK, now I understand the ratio.

However there are two things I think.

1. Since I have no intention at all to buy new heatsink or fans or whatever, just everything stock because Im on the tightest budget ever, i need to know what is the max frequency I can hit with the E6420 so that I still have stability in the system, with the stock parts (do you happen to know what FSB this is? If not then I guess I ask around in another topic), right?
So that for instance, if it was 333 (333*8 = 2.6 Ghz), 667 would work for me, as the 533 would be "not so good".
And in this case buying 800 means "do I have the extra bucks or not?".
But if lets say I can hit 400 Mhz with no sweat, all stock (400*8 = 3.1 Ghz), then Im gonna need the 800 Mhz as the 533/667 would be "not so good".
Or is this wrong and OC'ed E6420 @ 400 Mhz would still be good with a stock 533? :?

2. So basically the thing with the ratio is, 1:1 is the minimal and you should be fine, but if you have the bucks go for a bigger ratio that will provide better performance? (For example the aforementioned 2:1 ratio with 800 Mhz DDR2).

And Im considering the 533 because on amazon 800 are not really cheap (around $180 for OCZ whatever), but 533 ValueRAM ones are about $100, and 80 bucks is 80 bucks considering the shipping costs etc ;) 
(And as I have explained before, no, no other online retailer will take my credit card and there is nothing I can do to change this).

Thanks again for your time :) 
a b à CPUs
April 28, 2007 9:40:22 PM

Intel chipsets don't even drop below a 1:1 ratio, so you'll need at least DDR2-666 (PC2-5300) to run your bus at 333 (FSB1333) or at least DDR2-800 (PC2-6400) to run your bus at 400 (FSB1600).

That is, unless you can overclock your memory too.
!