Noob needs help...What speed memory best with E8400?

[donfm]

Ok I am lost when it comes to what speed memory I need with my mobo / cpu combination.
I am getting an E8400 CPU with a fsb of 1333mhz and a Gigabyte mobo which supports that speed and dual channel memory. I plan on overclocking a bit.

So what would be my best bet for stable performance in DDR2 memory. I am thinking PC8000 or PC 8500 but I really don't know. I plan on overclocking so I need some headroom.

Any suggestions would be appreciated. And if you could suggest some decent 4gb(2x2gb) memory I would appreciate that as well. I am overwhelmed by the sheer number of memory suppliers and combinations out there.

 

[DSF]

You said 4GB, but you also said 4x2GB. Did you mean 4 GB (2x2GB) or 8GB (4x2GB)?

DDR2-1000 will have enough headroom for any overclocking you plan to do. It basically comes down to which one has a better sale going on, as RAM has become quite cheap.

If your overclocking plans are mild, DDR2-800 is just fine to take that chip to 3.6GHz and possible even farther.

 

[donfm]

Sorry I meant 2X2gb.....for a total of 4 gb.

Can you suggest a specific memory please with a good track record on not failing? So DDR2-1066 would be overkill I suppose.

So realistically with the Gigabyte GA-EP45-UD3R and an E8400 core duo what would we be talking for possible overclocking speeds with DDR2-1000? It was suggested to me to get an E74000 and clock it to E8400 sppeds and save a buck or 3.

I wish there was a site that explained all this stuff so I could understand what the limits are for overclocking. If you know of a link I would like to read it.

 

[MTDEW]

e8400 has a multiplier of 9.
The multiplier times the front side bus = processor speed.
Then the front side bus times two = memory speed (because its DDR2 memory, which means double data rate)

So with ddr2 800 you'd get 3.6ghz
9x400fsb = 3.6ghz
400fsb x 2 = 800mhz / DDR2 800 (ddr2 is Double Data Rate so its the fsb times two ie: 400 x2 = 800)

With ddr2 1000 you'd get 4.5ghz
9x500fsb - 4.5ghz
500fsb x 2 = 1000mhz (DDR2 1000)

Realistically, you're not gonna get 4.5ghz, more likely between 3.6ghz and 4.0ghz overclocking an e8400, so DDR2 800 isnt quite enough to max out an e8400 overclock and DDR2 1000 is a little more than enough.

just get this and you'll be fine. (G.Skill DDR2 1000)
http://www.newegg.com/Product/...x?Item=N82E16820231145

 

[donfm]

Originally posted by: MTDEW
e8400 has a multiplier of 9.
The multiplier times the front side bus = processor speed.

So with ddr2 800 you'd get 3.6ghz
9x400fsb = 3.6ghz (ddr2 is Double Data Rate so its the fsb times two ie: 400 x2 = 800)

With ddr2 1000 you'd get 4.5ghz
9x500fsb - 4.5ghz
500fsb x 2 = 1000mhz (DDR2 1000)

Realistically, you're not gonna get 4.5ghz, more likely between 3.6ghz and 4.0ghz overclocking an e8400, so DDR2 800 isnt quite enough to max out an e8400 overclock and DDR2 1000 is a little more than enough.

just get this and you'll be fine. (G.Skill DDR2 1000)
http://www.newegg.com/Product/...x?Item=N82E16820231145

So then 1066 memory would just be a waste of money since its such a small increment over the 1000 in speed ???....its about the same price....is this memory a known overclocker?

 

[MTDEW]

I am getting an E8400 CPU with a fsb of 1333mhz and a Gigabyte mobo which supports that speed and dual channel memory. I plan on overclocking a bit.

Now here is where you're probably getting confused, like most new people.

The front side bus is "quad pumped" so to speak.
In other words, a cpu with a fsb of 1333mhz is usually referred to in the overclocking world as a 333mhz fsb.
Thats becuase 333mhz x 4 = 1333mhz. (they round up)

ddr2 800 would be good for 1600fsb.
400mhz fsb x 4 = 1600mhz

ddr2 1000 would be good for 2000fsb.
500mhz fsb x 4 = 2000mhz

 

[Zaxx]

If you motherboard natively supports 1066 (as a lot do now) then you will see the benefit of the 5:8 memery to fsb ratio. Right now it's a buyers market for DDR2...1066 is only slightly more than decent ddr2800 but deff worth a few $ more. I use Ocz..exclusively..

Here's Ocz's 1066 offerings (2x4GB)

http://www.newegg.com/Product/...me=4GB%20(2%20x%202GB)

The Platinum and Reaper editions are the best with low latencies/timmings of 5-5-5...

 

[MTDEW]

Originally posted by: donfm

Originally posted by: MTDEW
e8400 has a multiplier of 9.
The multiplier times the front side bus = processor speed.

So with ddr2 800 you'd get 3.6ghz
9x400fsb = 3.6ghz (ddr2 is Double Data Rate so its the fsb times two ie: 400 x2 = 800)

With ddr2 1000 you'd get 4.5ghz
9x500fsb - 4.5ghz
500fsb x 2 = 1000mhz (DDR2 1000)

Realistically, you're not gonna get 4.5ghz, more likely between 3.6ghz and 4.0ghz overclocking an e8400, so DDR2 800 isnt quite enough to max out an e8400 overclock and DDR2 1000 is a little more than enough.

just get this and you'll be fine. (G.Skill DDR2 1000)
http://www.newegg.com/Product/...x?Item=N82E16820231145

So then 1066 memory would just be a waste of money since its such a small increment over the 1000 in speed ???....its about the same price....is this memory a known overclocker?

With an e8400 you'll never get close to overclocking the DDR2 1000 memory.
The cpu would have to do more than 4.5ghz which it will not.

You can still get DDR2 1066 if you want, it wont hurt.
You'll just most like be only running it at DDR2 900 speeds max with an e8400 cpu.
Because 9 x 450fsb = 4050mhz (which is where most e8400's "top out")

 

[MTDEW]

Originally posted by: Movieman420
If you motherboard natively supports 1066 (as a lot do now) then you will see the benefit of the 5:8 memery to fsb ratio. Right now it's a buyers market for DDR2...1066 is only slightly more than decent ddr2800 but deff worth a few $ more. I use Ocz..exclusively..

Here's Ocz's 1066 offerings (2x4GB)

http://www.newegg.com/Product/...me=4GB%20(2%20x%202GB)

The Platinum and Reaper editions are the best with low latencies/timmings of 5-5-5...

He's right, theres no "rule" that you have to run the memory at 1:1.
Its not much of a performance boost to go above 1:1 , but it does give you "headroom" and certainly wont hurt.

 

[Blain]

Just use 1.8-1.9v PC2-6400, you'll be golden. :thumbsup:

Originally posted by: Zoinks
What's the best quality RAM?

Originally posted by: zerocool84
Corsair
Mushkin

And G.Skill

 

[MTDEW]

LOL
Looking back through all this, i can easily see how its so confusing if you're new overclocker.

Put it this way.

You'll need at least ddr2 1000 to be sure your e8400 overclock isnt held back at all by the memory.
And since ddr2 1066 isnt much more than ddr2 1000, theres no harm in buying that.

Once you have your cpu at its max overclock, then maybe you can run the ram higher than 1:1 with the fsb.

Im not a fan of the overclockers ram , i have to admit.
Im not saying its "bad", but .....
They sell memory thats "overvolted" already to hit the rated speeds.
And doesnt like to post at a lower voltage so you can set it to rated voltage.

I usually buy ram thats rated for 1.8 - 1.9v to be sure it will POST with a new build.


Some motherboards wont post with memory rated at 2.0v or more.
And that can be a pain, since you cant get the motherboard to post to set the voltage manually.

 

[francisA]

I've just been through some oc'ing on my Q9550 and UD3P. The Q9550 has a default of 333Mhz like the E8400. I do have G.Skill PI Blacks, DDR2 800.

I have brought my rig up to 475x8.5 for 4.038GHz and stable at that (8hrs Prime, 2hrs Orthos, 40passes IBT). As for the RAM, it was able to hold up till 950Mhz (DDR950) at slightly relaxed timings of 5-5-5-15 @ 1.9v.

If you're not going past 450 or 475, the DDR2 800s will work great for ya. It did for me. The PI Blacks are just amazing for the price.

I tried pumping up the FSB to 500Mhz for 4.250Mhz and gave the PI Blacks 2.0v. It posted, went into XP, but XP just fell on its face and hung, which tells me that the Q9550 could possibly sustain 500fsb but the PI Blacks may not. I dunno, I'm new to oc'ing but that's my observation. I don't want to give it way too much volts as I may use 'em for another build (based on my E5200)

So if you can reach 500 and beyond, then DDR2 1000 or DDR2 1066 will be better. I'm getting DDR2 1000 or 1100s soon.

 

[MTDEW]

Originally posted by: francisA
I've just been through some oc'ing on my Q9550 and UD3P. The Q9550 has a default of 333Mhz like the E8400. I do have G.Skill PI Blacks, DDR2 800.

I have brought my rig up to 475x8.5 for 4.038GHz and stable at that (8hrs Prime, 2hrs Orthos, 40passes IBT). As for the RAM, it was able to hold up till 950Mhz (DDR950) at slightly relaxed timings of 5-5-5-15 @ 1.9v.

If you're not going past 450 or 475, the DDR2 800s will work great for ya. It did for me. The PI Blacks are just amazing for the price.

I tried pumping up the FSB to 500Mhz for 4.250Mhz and gave the PI Blacks 2.0v. It posted, went into XP, but XP just hung, which tells me that the Q9550 could possibly sustain 500fsb but the PI Blacks may not. I dunno, I'm new to oc'ing but that's my observation.

So if you can reach 500 and beyond, then DDR2 1000 or DDR2 1066 will be better. I'm getting DDR2 1000 or 1100s soon.

LOL
Was staying away from considering how well his ram would overclock, since im sure he's confused already.

Nice q9550 overclock!

Anyway, as others including myself have noted.
Ive had great experiences with G.Skill memory.

As a matter of fact im running 8gb of the G.Skill DDR2 1000 i linked to above on my Gigabyte UD3P motherboard.
I ran an e8400 at 4ghz with it, and am currently running a q6600 with it.

 

[donfm]

Ok dumb question......you say you are pumping up the fsb to achieve greater speeds. Well what sets the limit on how far you can pump up the fsb on the processor. Let me see if I understand this...

If I say purchased 1066 memory....the theoretical fsb limit on the memory would be 1066/2=533mhz.

the theoretical max for the E8400 with that memory would be 9X533mhz=4.8ghz?

But that is just the limitation put on by the memory speed.

So what limits how far you can pump up the front side buss before the PSU says unh uh???

Is it just the heat factor? I realize these theoretical values are unapproachable.

 

[MTDEW]

Originally posted by: donfm
Ok dumb question......you say you are pumping up the fsb to achieve greater speeds. Well what sets the limit on how far you can pump up the fsb on the processor. Let me see if I understand this...

If I say purchased 1066 memory....the theoretical fsb limit on the memory would be 1066/2=533mhz.

the theoretical max for the E8400 with that memory would be 9X533mhz=4.8ghz?

But that is just the limitation put on by the memory speed.

So what limits how far you can pump up the front side buss before the PSU says unh uh???

The motherboard will have its limits on the fsb. (voltage/cooling on mobo also matters)
And the cpu does somewhat, some processors just dont like a high fsb, i have no idea why, maybe someone can explain that one, cuz i'd like to know the answer to that myself.

But the motherboard you're choosing (UD3R) will not crap out on FSB before your e8400 does.
but yeah, you can use the FSB to your advantage, by lowering the cpu multiplier.

9 x 450fsb = 4050mhz
8 x 500fsb = 4000mhz
In the very simple example above, assuming the cpu does 4ghz, you can drop the cpu multiplier to take advantage of a higher fsb.
But that usually requires more voltage to the mobo componnents and strains the system more (more heat), so theres always a "catch".

 

[MTDEW]

donfm,
Don't worry, it may seem so confusing now, but once you have the parts and take the time to learn to overclock and can see what the settings do frsthand, its actually really easy to understand.

The motherboard has its limits on overclocking just like a cpu.
And just like a cpu, voltage and heat both factor into how high a motherboard can overclock. (as well as quality of the board and quality of hardware used on the mobo)
So just like cpu's, you can have two identical motherboards and one may overclock a bit higher than another or run cooler or hotter.
(thats why people who water cool, like to put a motherboard chipset waterblock on their "loop" to help cool the mobo for better overclocks)

Same thing with memory overclocking.

You choose the Gigabyte UD3R for the same reason you chose an e8400.
They are both known for good overclocking, but results will vary a bit from one to the next.
You buy the hardware thats "known" / "proven" to be a good overclocker on average to help increase your chances of getting the perfect setup with a good overclock.
But by no means is any specific speed of overclock guaranteed.

 

[donfm]

I think I need to get a book on this subject. The deeper I get the more questions I have.....but thank you for taking the time to explain I really appreciate it MTDEW.....I am the kind of guy who needs to know why I am doing what I am doing. I can't just take it for granted..I suppose that is the geek in me.....lol

How is lowering the multiplier and thus lowering the speed by 50 Mhz in your example and increasing the fsb an advantage? Is it because the fsb is the bottleneck in the whole process of how fast data is processed and a higher fsb is advantageous?

This thread is turning into a short novel....laffing

 

[MTDEW]

Don't worry, you picked the right cpu and right motherboard. (e8400/ UD3R(or UD3P)
Now go get some DDR2 1000 or DDR2 1066 memory and a good HSF and you'll be set. :thumbsup:

Just like was said, good namebrands are. (and this will vary a WHOLE LOT due to opinion)
But nobody argues that the ones below are great choices.
G.Skill
Corsair
Mushskin

 

[MTDEW]

Originally posted by: donfm
I think I need to get a book on this subject. The deeper I get the more questions I have.....but thank you for taking the time to explain I really appreciate it MTDEW.....I am the kind of guy who needs to know why I am doing what I am doing. I can't just take it for granted..I suppose that is the geek in me.....lol

How is lowering the multiplier and thus lowering the speed by 50 Mhz in your example and increasing the fsb an advantage? Is it because the fsb is the bottleneck in the whole process of how fast data is processed and a higher fsb is advantageous?

This thread is turning into a short novel....laffing

The higher FSB will allow you to run your memory faster which gives you more memory bandwidth.
Which will negate the advantage the 50mhz on the cpu would have had.
So yeah, 8 x 500fsb would be faster as long as the memory timings remain the same.

I think i'll stop there, cuz memory timings will twist your brain in a knot...LOL
General rule of thumb on memory timings is....
Lower timings on memory really only matter a whole lot in benchmarks.
Always go with the fastest speed you can get from the memory without relaxing the cas latency, as it usually yields better results then running memory slower with tighter timings.
Only tighten memory timings once you have your max overclock finished and stable, then use tighter timings to get that extra "tweak".

 

[MTDEW]

Originally posted by: donfm
I think I need to get a book on this subject. The deeper I get the more questions I have.....but thank you for taking the time to explain I really appreciate it MTDEW.....I am the kind of guy who needs to know why I am doing what I am doing. I can't just take it for granted..I suppose that is the geek in me.....lol

How is lowering the multiplier and thus lowering the speed by 50 Mhz in your example and increasing the fsb an advantage? Is it because the fsb is the bottleneck in the whole process of how fast data is processed and a higher fsb is advantageous?

This thread is turning into a short novel....laffing

Oh and be careful, this hobby is EXTREMELY addictive.

I always have 4 pcs in my house that are usually near "top of the line" hardware.
Simply cuz i cant resist buying new hardware to play with.
Do i use all four pcs every day? NOPE!

This is the greatest hobby in the world, cuz theres always something newer and faster to play with as soon as you're done building / tweaking your last setup.

It is addictive and these guys here on anandtech dont help one bit to keeping it under control. (especially the guys in the video card forum) LOL

 

[donfm]

I think I will be spending a lot of time HERE for the next few days....

Alright...I am ready to go ahead with my purchase...thanks for the info and your patience with a noob overclocker.

This forum is a wealth of knowledge for the hobbyist..

 

[MTDEW]

And this is one of the best places to come for accurate advice.

Because there are so many knowledgable members, that if someone gives bad/inaccurate advice, there are always people here who will jump in and set you straight with facts.

Too many times on other forums people give advice based on there own personal opinion without stating so and posting those opinions as facts, which misleads people looking for legitimate help.

example:
Just try going to the Operating System forum and start a thread that says Vista is a buggy mess.
I'll bet its less than 30sec before some posts you have no idea what what you're talking about....LOL

Theres lots of good/knowledgable members here, and i tend to do a search here for answers if i need them before even searching Google.

Good Luck with your new setup.