Building first Intel system, need help with FSB and memory.

Caxus

So i've been used to AMD for the last few years and i've forgotten how to do all this fsb and memory speed matching. I'm looking to get a Core 2 Duo E6750 which has a 1333 FSB. If i get this Gigabyte motherboard with it which has a memory standard of 1066, what kind of memory should i be looking for?

Thrax

The chip uses a 333MHz <b>actual</b> FSB, which is DDR2-667 (Or PC2-5300). Intels respond well to running the bus asynchronously. 1066 is 533 actual megaherz, or about 50% faster than 333. It's also called 1066, or PC2-8000.

The best you'll be able to do is a 333MHz FSB on a 3:2 divider giving you 500MHz/PC2-8000/DDR-1000 for the RAM.

Caxus

Would I be better off choosing a MB that can use 1333 DDR2 memory?

Thrax

That'd be 666MHz DDR2, and they don't make it.

Caxus

Do you know of any good guides I could read that explain all this stuff pretty well?

Caxus

Thrax wrote:

The best you'll be able to do is a 333MHz FSB on a 3:2 divider giving you 500MHz/PC2-8000/DDR-1000 for the RAM.

Is that RAM type the best I can do with that cpu period or just with that particular motherboard?

Thrax

Here's how it works on Intel platforms:

There's the FSB speed.
There's the memory speed.
These can be equal, or separate.

The enthusiast community speaks of FSBs in <b>actual</b> megahertz. Be it 266, 333, 400, 500 or 533. When it comes to RAM, most people speak of the bandwidth (6400, 5300, 8000, 8400, etc.)

Now here's where it gets confusing:
Intel rates all their chips with the FSB * 4. That's why 333.33 <b>real</b> MHz is 1333 on Intel adverts.
RAM is FSB * 2, which is why a 333MHz FSB uses DDR2-667.
FSB * 2 * 8 is the bandwidth of the memory, which is why DDR2-667 is also known as PC2-5300.

Here's a quick cheat sheat:
266MHz FSB = DDR2-533 = PC2-4200
333MHz FSB = DDR2-667 = PC2-5300
400MHz FSB = DDR2-800 = PC2-6700
500MHz FSB = DDR2-1000 = PC2-8000
533MHz FSB = DDR2-1066 = PC2-8500

Now, this assumes you're running the FSB and RAM at the same speed which Intel does not do by default. It's not like old Athlon XPs.

So, there are these neat things called dividers. It's two numbers that you, literally, divide to get a number. You multiply the FSB by this number, and that is the resulting RAM speed. The most common ones are as follows:

1:2 = 0.50
2:3 = 0.67
3:4 = 0.75
4:5 = 0.80
5:6 = 0.83
6:7 = 0.85
7:6 = 1.16
6:5 = 1.20
5:4 = 1.25
4:3 = 1.33
3:2 = 1.50
2:1 = 2.00

Now, Intel officially recognizes two FSB speeds for their chips:
266
333

Now, here are the RAM speeds you can run with 266 FSB Core 2s (On most motherboards worth their salt):
266 FSB @ 1:1 (1.00) = 266.66MHz RAM * 2 = DDR2-533 * 8 = PC2-4300.
266 FSB @ 5:4 (1.25) = 333MHz RAM * 2 = DDR2-667 * 8 = PC2-5400.
266 FSB @ 3:2 (1.5) = 400MHz RAM * 2 = DDR2-800 * 8 = PC2-6400.
266 FSB @ 2:1 (2.0) = 533MHz RAM * 2 = DDR2-1066 * 8 = PC2-8500.

Now, here are the RAM speeds you can run with 333 FSB Core 2s (On most motherboards worth their salt):
333 FSB @ 4:5 (0.80) = 266MHz RAM * 2 = DDR2-533 * 8 = PC2-4300
333 FSB @ 1:1 (1.00) = 333.33MHz RAM * 2 = DDR2-667 * 8 = PC2-5400
333 FSB @ 6:5 (1.20) = 400MHz RAM * 2 = DDR2-800 * 8 = PC2-6700
333 FSB @ 3:2 (1.50) = 500MHz RAM * 2 = DDR2-1000 * 8 = PC2-8000

Now, nothing is stopping you from running ANY FSB frequency at 1:1 with your RAM, but you better make damn sure that your components can handle it. A lot of overclockers do 500MHz FSB, 500MHz RAM and use PC2-8000/DDR2-1000.

In summary:
333MHz chips have a faster FSB from chip to components, but slower from memory to components.
266MHz chips have a slower FSB from chip to components, but faster from memory components.

This assumes you're using the fastest possible RAM with your board, and <b>not overclocking</b>. If you overclock, you can get damn near any FSB and memory speed you want if your components are good. Does this make more sense?

//EDIT: For clarity.

NiGHTS

This needs to be an article.

Thelemech

NiGHTS wrote:

This needs to be an article.

Agreed.

Thelemech

Thrax wrote:

Here's how it works on Intel platforms:

There's the FSB speed.
There's the memory speed.
These can be equal, or separate.

The enthusiast community speaks of FSBs in actual megahertz. Be it 266, 333, 400, 500 or 533. When it comes to RAM, most people speak of the bandwidth (6400, 5300, 8000, 8400, etc.)

Now here's where it gets confusing:
Intel rates all their chips with the FSB * 4. That's why 333.33 real MHz is 1333 on Intel adverts.
RAM is FSB * 2, which is why a 333MHz FSB uses DDR2-667.
FSB * 2 * 8 is the bandwidth of the memory, which is why DDR2-667 is also known as PC2-5300.

Here's a quick cheat sheat:
266MHz FSB = DDR2-533 = PC2-4200
333MHz FSB = DDR2-667 = PC2-5300
400MHz FSB = DDR2-800 = PC2-6700
500MHz FSB = DDR2-1000 = PC2-8000
533MHz FSB = DDR2-1066 = PC2-8500

Now, this assumes you're running the FSB and RAM at the same speed which Intel does not do by default. It's not like old Athlon XPs.

So, there are these neat things called dividers. It's two numbers that you, literally, divide to get a number. You multiply the FSB by this number, and that is the resulting RAM speed. The most common ones are as follows:

1:2 = 0.50
2:3 = 0.67
3:4 = 0.75
4:5 = 0.80
5:6 = 0.83
6:7 = 0.85
7:6 = 1.16
6:5 = 1.20
5:4 = 1.25
4:3 = 1.33
3:2 = 1.50
2:1 = 2.00

Now, Intel officially recognizes two FSB speeds for their chips:
266
333

Now, here are the RAM speeds you can run with 266 FSB Core 2s (On most motherboards worth their salt):
266 FSB @ 1:1 (1.00) = 266.66MHz RAM * 2 = DDR2-533 * 8 = PC2-4300.
266 FSB @ 5:4 (1.25) = 333MHz RAM * 2 = DDR2-667 * 8 = PC2-5400.
266 FSB @ 3:2 (1.5) = 400MHz RAM * 2 = DDR2-800 * 8 = PC2-6400.
266 FSB @ 2:1 (2.0) = 533MHz RAM * 2 = DDR2-1066 * 8 = PC2-8500.

Now, here are the RAM speeds you can run with 333 FSB Core 2s (On most motherboards worth their salt):
333 FSB @ 4:5 (0.80) = 266MHz RAM * 2 = DDR2-533 * 8 = PC2-4300
333 FSB @ 1:1 (1.00) = 333.33MHz RAM * 2 = DDR2-667 * 8 = PC2-5400
333 FSB @ 6:5 (1.20) = 400MHz RAM * 2 = DDR2-800 * 8 = PC2-6700
333 FSB @ 3:2 (1.50) = 500MHz RAM * 2 = DDR2-1000 * 8 = PC2-8000

Now, nothing is stopping you from running ANY FSB frequency at 1:1 with your RAM, but you better make damn sure that your components can handle it. A lot of overclockers do 500MHz FSB, 500MHz RAM and use PC2-8000/DDR2-1000.

In summary:
333MHz chips have a faster FSB from chip to components, but slower from memory to components.
266MHz chips have a slower FSB from chip to components, but faster from memory components.

This assumes you're using the fastest possible RAM with your board, and not overclocking. If you overclock, you can get damn near any FSB and memory speed you want if your components are good. Does this make more sense?

//EDIT: For clarity.

This right here. (in re to *"this Needs to be an article"*)

Caxus

I've noticed that several of the benchmarks i've seen using this cpu also use DDR2 800 memory. There's even one on anandtech that compares the 6750 to the 6700 and they use DDR2 800 on both. Is there something to be gained by using the lower speed memory at the tighter timings or would it be best to go with DDR2 1066 for this cpu? I always just assumed that you'd want to use the fastest memory your motherboard can handle.

Thrax

800 is the default memory that Intel officially endorses as a baseline. It's good to use faster memory if the board can handle it.

Snarkasm

DDR2-800 is just the most common and cost-efficient, from what I understand. Plus the good stuff is overclockable to 1066 and farther anyhow.

Caxus

So I should plan to run the memory at DDR 1000 whether I buy memory that's rated at that speed or overclock some DDR2 800? That's going to be the sweetspot for that cpu?

Edit: Or I guess get some DDR2 1066 and run it at 1000 with the 3:2 divider?

Leonardo

So I should plan to run the memory at DDR 1000 whether I buy memory that's rated at that speed or overclock some DDR2 800?

No. You can run DDR2 800 at DDR2 800+ IF it is overclock capable of those higher frequencies. Not all of it is.

Look at the overclocks for my Q6600 systems in my signature. All the DRAM I'm running is PC2 6400 (DDR2 800). I've got it running at speeds ranging from 800 to close to 900. Some of it, I'm sure, will run at higher frequencies, but I just haven't experimented in that range yet. The A-Data I have won't overclock much at all.

(oops, the multiplier/FSB settings in signature may not be up to date - I'll check when I get home this evening)

Caxus

Leonardo wrote:

No. You can run DDR2 800 at DDR2 800+ IF it is overclock capable of those higher frequencies. Not all of it is.

Look at the overclocks for my Q6600 systems in my signature. All the DRAM I'm running is PC2 6400 (DDR2 800). I've got it running at speeds ranging from 800 to close to 900. Some of it, I'm sure, will run at higher frequencies, but I just haven't experimented in that range yet. The A-Data I have won't overclock much at all.

But would your systems run faster if you upgraded to DDR2 1066 or is there a reason to stick to DDR2 800 that I'm still not getting?

Snarkasm

If the board can support 1066, there's no reason not to get it besides the dollar values, I believe.

Caxus

From what I can tell on newegg, if i'm on a budget and not going to be seriously overclocking if any at all I should probably go with 2GB of DDR2 1066 for $80 rather than 2GB of DDR2 800 for $45.

Snarkasm

Can't say I understand that logic. You sure you phrased that correctly?

Sonorous

More often that not I have been seeing a ton of ram rated for speeds like 1066 and higher, that won't run at that speed if you just slap it in the mobo. A lot of the cases I have seen from reviews at Newegg and such seem to require manual setting of voltage and such. So the way I see it, you are already messing with settings in the BIOS, why not just go all out and get slower, more overclockable ram? You might save some money and get a better rig from that type of thinking. I just picked up a 4 gig kit of G.Skill DDR2 800 for 115. I'll let you know how it does.

Caxus

MJancaitis wrote:

Can't say I understand that logic. You sure you phrased that correctly?

What I mean is that I don't want to get fancy since i'm not very familiar with intel systems. I'd rather just get ram that's rated at 1066 rather than try to overclock 800 and mess with voltages and cooling options and such. $35 is a very small price to pay for the extra speed with simplicity.

Snarkasm

I see. Can't argue with that, then. Make sure that the performance benefit from 800 to 1066 is worth the same amount to you.

Leonardo

Caxus, I agree with you. With 1066 you have so much more headroom for CPU multiplier and FSB combinations. It definitely would make it easier. I don't run any 1066 and don't know the who's who on it. Members here can help you make a selection. G.Skill and Geil are usually spot on as to their default performance/settings compared to what's printed on the packaging.

Caxus

The Trickster wrote:

More often that not I have been seeing a ton of ram rated for speeds like 1066 and higher, that won't run at that speed if you just slap it in the mobo. A lot of the cases I have seen from reviews at Newegg and such seem to require manual setting of voltage and such. So the way I see it, you are already messing with settings in the BIOS, why not just go all out and get slower, more overclockable ram? You might save some money and get a better rig from that type of thinking. I just picked up a 4 gig kit of G.Skill DDR2 800 for 115. I'll let you know how it does.

Now I'm getting a bit confused. I thought the whole point of rating RAM at a certain speed was that it was tested and is stable at that speed and that when a user overclocks he's basically just taking advantage of the strictness of the testing and pushing it a bit further than the manufacturer was comfortable rating it.

It seems odd to pay more for "quality" slower RAM just so that I can overclock it to speeds that other faster cheap RAM is rated at to begin with. For example, if 2x1 GB of cheap DDR2 800 is $45 and 2x1 GB of cheap DDR2 1066 is $80, should I pay $80 for 2x1 GB of higher quality DDR2 800 just because it will be more likely to overclock to 1066?

Leonardo

should I pay $80 for 2x1 GB of higher quality DDR2 800 just because it will be more likely to overclock to 1066?

No! That isn't logical by my mind either. That wasn't really the point. The Trickster was pointing out that for just a little more than you'd get the 2X1GB 1066 you could get 4XGB kit of 800. I would spring for that, but then, I'm quite comfortable overclocking Intel systems.

Snarkasm

Leo's right, but you also shouldn't get just cheap 1066. Regardless of the type you get, if you want a really solid long-lasting system, you can't just go with any Patriot brand or anything. Go with the good names for a few dollars more and you'll get more than their worth out of it. If you had a choice between, say, Ballistix DDR2-800 for $50 and some Patriot DDR2-1066 for $80, it might just be me, but I'd go for the Ballistix every day of the week and twice on Sunday. Others can feel free to correct me from their personal experience or whatever, but that's what my experience has worked out to.

To clarify, you don't need Ballistix or OCZ Reaper edition or anything every time, but the middle-tier brands are stronger in my experience than the bottom tier, and to me, middle-top tier 800 is a stronger option to me than lower-tier 1066.

Leonardo

I would definitely not pay $50 difference between brands for same quantity of same speed (rated frequency, that is) DDR2. $20 or $30, yes, probably - if the more expensive brand was good for significantly higher clocks. For real world computer usage, quantity and stock frequency are so much more important than overclocking headroom and tight timings.

BTW, the RAM that people tend to have the most problems with is the higher quality OCZ. Often, the motherboard default RAM voltages are lower than the specified minimum voltages for the RAM. That's not a fault with OCZ, it's just the way it's designed. But then, this is not a problem if the user increases the voltage before installing the RAM.

Caxus

I would probably either go with

http://www.newegg.com/Product/Product.aspx?Item=N82E16820134586

or

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231098

The only reason I usually pay more for RAM is to get tighter timings which doesn't seem to be much of an issue with this high speed DDR2.

Sonorous

Leonardo wrote:

No! That isn't logical by my mind either. That wasn't really the point. The Trickster was pointing out that for just a little more than you'd get the 2X1GB 1066 you could get 4XGB kit of 800. I would spring for that, but then, I'm quite comfortable overclocking Intel systems.

Exactly! You would most likely benefit from 4GBs of ddr2 800 over the 2 GB of ddr2 1066. I have run corsair dominator 1066 at both 1066 and 1800 speeds, and would not have been able to tell the difference if I didn't have 3dmark saying "HEY you got a better score". Having decent ram in a larger quantity seems like the better option for the long run than top of the line ram in a smaller quantity, and if you feel like tweaking some stuff, there are options out there that will grant you that ability. Out of all the components that a consumer has to choose from when building a PC, I think ram is the hardest to choose.

Thrax

The kingston is good stuff.

Caxus

The Trickster wrote:

Exactly! You would most likely benefit from 4GBs of ddr2 800 over the 2 GB of ddr2 1066. I have run corsair dominator 1066 at both 1066 and 1800 speeds, and would not have been able to tell the difference if I didn't have 3dmark saying "HEY you got a better score". Having decent ram in a larger quantity seems like the better option for the long run than top of the line ram in a smaller quantity, and if you feel like tweaking some stuff, there are options out there that will grant you that ability. Out of all the components that a consumer has to choose from when building a PC, I think ram is the hardest to choose.

I don't think I would see any difference at all in going from 2gb to 4gb for games. I have yet to find a game that uses even half of 2gb.