CPU For New Computer

Hi all,
Been a long 4 years since I built myself a new computer, but the time has arrived.

So far I have gotten a Lian Li case, a Thermaltake ps, 2-WD HD's, Thermalright Ultima heatsink, Gigabyte P35 xxxP motherboard, and a set, 2-gigs of Corsair XMS 800 memory.

My question is this; Which of the Core 2 Duo's under 200 bux would you recommend for the Corsair memory? I think the Conroes with the 1066 fsb would be ok, but if so I need pointing in the right direction on how to set up my memory to oc it to match the fsb of the 1066 cpu?

Any help would be appreciated....

Thanks,
Mike

There's an awesome deal on the e6600 right now, but I think they just went OoS. The e6750 is a great CPU as well...I think mwave has it for $194, but you might want to search around for better deals. It does have a 1333 FSB, but that doesn't mean your RAM has to run that fast. It's actually half that. You only need DDR2-533 to run 1:1 w/ a 1066FSB, and you only need DDR2-667 to run 1:1 w/ a 1333FSB. DDR2-800 will give you plenty of headroom either way.

Running memory 1:1

Unless you use a divider (or in Intel's case a multiplier) your memory will always run 1:1 with the CPU. The memory essentially goes along for the ride. If you run a 1066 CPU stock you will be running the FSB at 266 and the memory will also run at 266 (x2) or DDR2-533. If you increase the FSB to 300 the memory will be running DDR2-600. If you manually change the strap (multiplier) then you will have the memory running faster than the CPU from a frequency perspective. This is OK as long as the memory can do it. If you buy 1066 memory to run with a 1066 CPU it doesn't mean the memory is running 1066 when you run the CPU at stock. You are only running the memory at 2x what ever you set the FSB to. The 1066 rating of the memory means it will run at that speed at the given timings (typically 5-5-5-15) at a given voltage (typically 2.2v). To get the memory to run at that speed you will need to run the FSB at 533 and many boards will not do that, although many will. Your Gigabyte board should do that. In order to achieve that high of a FSB you will need to lower the multi of the CPU to 7 to get a 3.5 or 3.6GHz OC. So, in your case the best CPU right now for under $200 would be the E6550. They OC well and run relatively cool. Or you could spend a few more $$$ and get the E6750 (my recommendation) as it has an 8 multi and will give you more leeway as far as OCing goes. I have seen the E6750 go to 4GHz under good air cooling so that means you would be running a 500FSB x 8 multi which if you run the memory at 1:1 then you will be running at DDR2-1000 which is excellent. One more thing to keep in mind, if you buy DDR2-800 memory it doesn't mean it won't run at DDR2-1000. You will just have to bump the vdimm a little and loosen the timings. Example: I use Crucial Ballistix DDR2-800. I can run it at DDR2-667 at 3-3-3-8 timings with 2.2v, I can run it at DDR2-800 at 4-4-4-9 timings with 2.2vdimm, and I can run it at DDR2-1066 at 5-5-5-15 with 2.2vdimm. When you bought your Corsairs the only thing those numers/specs mean is that those modules are guaranteed to run at DDR2-800 with certain timings and at certain vdimm (called out in the specs). It will run at amny other speeds and timings.

Hi Jason,
I was reading about your Xeon and mobo problems in your thread next to mine last night when your responded to my thread. Gee you've been on a real bummer with the cpu and mobo. I've had had Asus, Epox and Abit mobos b4 and I've used several other types building systems for other people. Right now I am running a Asus P4PE. It's as old as Methuselah, coming over on the Ark!--lol Been real good to me though. I consider it one of the better Asus mobos to come along. I like Asus and would consider them as my second choice, that is mainly because they are so quirky. As you said in your post last night, they are tough to get started but once done they are solid.

Over time I have lost all credibility for Abit. I used to be strictly Abit, but they continueally have issues, not just being real quirky but with broken features that seems to always be needing a bios update. As for the matrix raids, the High Point Raids that came on Abits was worse than a bad joke. (Abit has also had MANY hardware problems that I had the luxury of experiencing personally.) I finally purchased myself a raid controller card and never looked back, doing away with buying the onboard raids. The quitting Abit altogether and going Asus.

However this time, because of money constraints I will be using the raid feature on the Gigabyte mobo, plus Gigabyte has been solid with their raid in the past. Well actually that is why I went Gigabyte, they simply have the most solid and straight foreward mobos I have ever used. Maybe they don't oc quiet as high as Asus or Abit but they are definitely of better engineering, specifically concerning not being quirky. I say it is the best trade off in my case and I'd never notice the difference in the final oc'ing performance.

As for the memory; what multipliers were available for the Gigabyte P35? I guess as sofarfrome stated in his post, I need a multiplier that would work for the e6750 and 1333 fsb if I went that route. So what multiplier would that be and I guess you saw that multiplier on your Gigabyte P35?

I used to post on here quit frequently, but in May of 2004 I left my now ex-wife of 15 years because of problems she couldn't overcome. Pulling up stakes didn't leave me any time for the forum here, nor much time to even be on the computer. Well that a little over 3 years ago and I'm still going to court concerning the property settlement. Oddly it seems she may actually get my old computer, the one I am on now. Well I needed a new one anyways.....

^^^Mike, you will never get your memory to DDR2-1333. No way, ever. Please, do not worry about multipliers yet. Set your memory ratio to 2.0 in bios (1:1) and start raising the FSB until you find what the CPU wants to run at. If you choose the E6750 you will be starting with a 333FSB (333x8=2.66GHz) therefore your memory will be runnig at DDR2-666. By the time you get to 500FSB or 4.0GHz your memory will be running DDR2-1000. If that Corsair you are looking at will go beyond that then count yourself as lucky. And frankly, unless you already have the Corsair memory I suggest you buy the Crucial DDR2-800 modules. I think newegg still has them for $80 AMIR.

Ok sofarfrome,
I'm getting to'ya!

Gee so much has been added in adjusting the memory in the last few years.... phew....

OK as I understand it the Corsair memory 800 that I purchased, got it this week from Newegg for 57 bux after rebate.... initially runs at 333 and I use the strap or ratio of 2 which effectively multiplies the memory to 667. From there I will start oc'ing the memory. And for each step, 1 mhz that I increase the memory I will be increasing the cpu oc by a factor of 8 mhz because the e6750 has a multiplier of 8. I already knew about the cpu mulitpliers, just I wasn't sure of the terminology for increasing the memory from its' initial 333.... So far as the Corsair memory oc'ing, I have read of peeps going up to about 1100. Not that I expect that much, just I want to be sure it can be made to work with the different fsb of the different cpus. That was a lot of help in your advice on your setting up the memory timings in your rig.

Only thing I am lacking in actually putting my rig together is the cpu, a video card, and finally a DVD burner that I am just getting ready to order from Newegg. If I can decide on the cpu today I may submit the cpu along with the DVD burner for an order. I usually buy my video cards locally because of the likely possibility of having to return it for problems. Much easier than mailing it off.

Still need an OS also but at the moment I'm thinking of installing a Linux version, Fudora or Fiesty Fawn.

Thanks so much!
Any thoughts are greatly appreciated,
Mike

Just to clarify, You do not increase the memory speed per se, you increase the FSB of the CPU and the memory goes along for the ride as long as your memory is capable of running at the FSB you have dialed in. Your E6750 has a 333MHz FSB that is quad pumped so 333x4 = 1333MHz (approximately). Your memory needs to be capable of 667MHz speed to match the speed of the CPU. Since intel does not use dividers it is important to make sure the modules will run at the stock rated speed of the CPU. Now, as you increase the FSB to say 400 now the CPU is running at 400x4 = 1600MHz effective FSB and your memory needs to be able to run at 800MHz speed which those Corsairs are designed and guaranteed to do. You may find that these modules will run much higher but you will need to loosen the timings and increase vdimm. You may also find that your CPU will reach a limit at say 450FSB but your memory has some headroom left to OC even more. Now is where the multipliers come in. If 450 is the CPU FSB limit then you can select a multiplier like 5:4 and run the memory at 1125. I would prefer to run the mem at 1:1, in this case 900MHz, but with tighter timings.

Hope this helps.

The CPU multiplier has nothing to do with memory speed. If you are using the 1:1 ratio, then memory frequency goes up exactly the same as FSB. So, the 1333 system bus processor like the E6750 is quad pumped, so it's really 333 FSB (333X4=1333). Let's say you O/C your CPU to 400 FSB (3.2 gig with the E6750). Using the 1:1 ratio, memory frequency is 400 MHz. DDR2 is like DDR where you double it for actual memory speed, so that gives you DDR2-800 speed, which is exactly what your RAM is rated at. Most good quality RAM will overclock to DDR2-900 with a bump or two in voltage. That's 450 FSB, meaning your system is running at 3.6 gig using the E6750 as an example. Obviously, if you use a different memory ratio, you have to do a different calulation. Clear as mud, huh?

sofarfrome,
Thanks for crash course. I've seemed to have missed a little the last few years...

Anywho, I think I'm catching on a little but you brought up a question.
You stated, "Your E6750 has a 333MHz FSB that is quad pumped so 333x4 = 1333MHz (approximately)."
Then in the next sentence you stated, "Your memory needs to be capable of 667MHz speed to match the speed of the CPU."
Now, how does the 333 Mhz fsb of the cpu turn into 667 Mhz to match the speed of the cpu? I can understand the memory being capable of 400 Mhz fsb and quad pumping it to 1600 Mhz. And I can understand going to about 450 Mhz. However you lose me again when you go back down to 1125? I mean if this memory works so well up to 1600 Mhz and the cpu fsb is calling for 1333 it would seem that is about a 266 Mhz over, which would be figured in the oc of the cpu? But my real question is; wouldn't this 266 Mhz (1600 Mhz by quad pumping the 400 Mhz) be the guaranteed limits of the memory, and there should be another 50 Mhz or so to add to that, as you stated, which would put the practical limits of the memory at about 1800 Mhz unless we started using the multiplier? About the only thing I am familiar with is the multiplier as it was used on the previous generations of Intel cpus.

As it stands now, do you still recommend the e6750 over anything else in the 200 buck range, as well as the bang for buck we get? I was originally thinking of upgrading to a Penryn when hey came out, but if I can get a good nuff cpu now, for abou 200 bux I may put off the Penyrn untill middl of the year. What about the Xeon that Jason was talking about in his thread? Anyhow at this point I am still entertaining other options but it still needs to be in the 200 to 250 range. Or another way to ask is; what would be the best bang for the buck considering any reasonable price?

Thanks again,
Mike

batboy said:

The CPU multiplier has nothing to do with memory speed.

Click to expand...

I was not referring to the CPU multi...Intel does not have dividers per se, they have multipliers for the memory.

In the Gigabyte BIOS the RAM multipliers are listed as 2.0, 2.4, 2.5, 3.0, 4.0. I probably missed some in there, but you get the point. Basically you multiply the FSB by these numbers to get your final RAM speed. In the beginning you'll want to run it at 2.0 (this is the 1:1 ratio). Make sure you set the DRAM voltage as well. The default is 1.8v, but it isn't listed in the BIOS. It just says +0.1, +0.2, etc. My RAM is 2.2v RAM, so I set it to +0.4v.

Your FSB will start at 333 (some programs show the FSB as quad-pumped 4x333=1333, but the Gigabyte BIOS shows it at 333). As you raise the FSB in 1MHz increments the RAM speed will increase in increments of 2. I know it sounds like it's in a 2:1 ratio, but it isn't really.

CPU speed will increase in increments of 8 (or whatever your multiplier is).

Starting out you should get your RAM voltage and timings set as to spec, and then boot to make sure everything is running right. For now you may want to keep your voltages on auto, and then try raising your FSB to 400. If this works, test for stability, and temps. If your good try setting all your voltages besides DRAM, and Vcore to the minimum value, and see if it still works, and test again. Then you can try setting the Vcore to 1.4v, and keep reducing it and testing for stability along the way. At this point you'll have a good OC, and a better understanding of how everything works. You can then try to go higher if you want. If Vcore isn't helping you get any higher, you can try dropping the multiplier (turn 8x down to 7x), and then you can see if it's the FSB holding you back. If so you can up the NB, FSB, and maybe SB voltages to get past this hurdle, and then set your multi back to 8, and try to climb again. Rinse, lather, repeat!

Make sure to keep temps in check, and don't raise the Vcore too much. A lot of people say 1.5-1.55v is the limit on air. I've gone higher, though, but not for long.

BTW...you may want to follow Bings UVOC steps to see if you have a good HS mount before you start climbing too high. Too much delta means it's time to re-mount, and a little AS5 goes a long way!

x3210 is a great deal if you want quad. It's what I chose. It'll cost you about $270, though. If $200 is where you wanna be then go w/ the e6750.

As far as your confusion about memory speeds, I'll try to explain. DDR2-800 is actually running at 400MHz. I think the reason they call it "800" is b/c it is running in dual channel, and w/ every tick of the clock data is simultaneously being transferred from each stick giving you the same amount of data as if you had 1 stick running at 800MHz. So when your FSB is set to 333 (it's "effective" speed is 1333 b/c there are 4 lanes for data to travel) your RAM gets set to 667 (667 is the "effective" speed, it is actually running at 333 w/ 2 lanes for the data to travel). Since your FSB and RAM are "actually" both running at 333MHz this is called a 1:1 ratio. As you increase your FSB your RAM will increase at the same rate. Make sense?

^^^Mike,



CPU: 333FSB x 4 = 1333MHz FSB or 2.66GHz on an 8x multi (or CPU to NB ratio).

memory: 667MHz x 2 = ~1333MHz (1334 actually), memory will always run 2x what the FSB is set at which is 1/2 what the quad pumped frequency is, provided you run the memory 1:1. On the Gigabyte boards they use 2.0 as the multi/divider to run 1:1 but they have others, which are your NB to memory ratio) that allow you to OC the memory more than the CPU hence ending up with an 1125 memory OC. However, unlike AMD and nvidia chipsets you can not under clock the memory while overclocking the CPU. Which is a great scenario if you have cheap ram that doesn't run as fast as your CPU FSB.

Look at it this way:

333 set FSB = ~667MHz memory speed on a 1:1 divider/ratio; 1333 FSB quad pumped
375 set FSB = 750MHz memory speed 1:1; 1500Mhz FSB quad pumped
400 set FSB = 800MHz memory speed 1:1; 1600Mhz FSB quad pumped
450 set FSB = 900MHz memory speed 1:1; 1800Mhz FSB quad pumped

now change the memory ratio to 5:4

333 set FSB = ~833MHz memory speed on a 5:4 divider/ratio; 1333 FSB quad pumped
375 set FSB = 937MHz memory speed 5:4; 1500Mhz FSB quad pumped
400 set FSB = 1000MHz memory speed 5:4; 1600Mhz FSB quad pumped
450 set FSB = 1125MHz memory speed 5:4; 1800Mhz FSB quad pumped

And yes, I would still recommend the E6750 over anything else available right now for under $200. But if you can swing the extra $70 or so the x3210 G0 stepping CPUs are great. I have mine in right now and it is running 3.2GHz at 1.27vcore running P95 small ffts for stability test. It has been running for an hour and I also am using it to write this and surf the net.

Jason and sofarfrome,
Thanks so very much on the classroom training today!
I have definitely learned a lot, thanks to you two!
This memory business was not how I preconceived it to be...... but isn't that the case in most things?
Sofarfrome, your last post just reconfirmed what I was understanding from Jason's last post, so yeah it would be kind'of hard to lose me now... Thanks again guys.

As for the cpu, guess I'll go ahead and order that e6750 in a few minutes, along with a Samsung DVD burner I had picked out.... On a down note, I had to scrimp somewhere and it looks like it will be the video card. I had hoped to make a multimedia rig out of this but I can't go that far just yet. Too many other things to cover at the same time. (I'm actually having to speed up my time table just a little, but I'm due for a new computer anyways.) Maybe around xmas when the new nvidia cards comes out......

And I'm still carrying over several things from my old computer, couple HDs, external DVD burner and a Yamaha CD burner, webcam, printer, scanner, keyboard and LCD monitor. All of it at least 4 or 5 years old..... phew. If only this new rig would last as long.

As for the raid in my old system, it's on a pci card and it's ran almost flawless all these years.

btw, I got in my heatsink and 120mm fans while writing this.

So Jason; how are you coming along with your new toy?

Thanks again,
Mike

I've been dropping the Vcore slowly, but I just got an error in P95, so I'm going to have to bump it back up to 1.4875 (I'm at 1.475 now) to be stable. I still need to test overnight, but I think 1.5V will be the most I'll need to be stable at 3.6GHz. Reference voltage set to x.63 seems to have the most stability so far.

My RAM's at 900 5-5-5-15 2T right now, but I think I can tighten it up. Before I do that, though, I'm going to drop the multi to 7x, and see how far the FSB will go. I also need to do a UVOC at stock for Bing.

The only problem is that my wife will be home around 7pm, and I promised I'd spend some time w/ her. She's that I've been glued to the PC for the past month, and haven't been paying her any attention!

Get a Q6600 and rock out.

Quad core and overclockable, not to mention CHEAP!

Teh Governator said:

Get a Q6600 and rock out.

Quad core and overclockable, not to mention CHEAP!

Click to expand...

That's what I'm doing...

Believe I'll wait for Penryn for the quad core. That's a reason I wanted to limit myself to less than 200 bux on a cpu.

Mike