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New CPU. Should RAM speed match FSB?

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July 13, 2011 3:39:40 AM

I recently had the fortune to come upon a new quad core Intel Core i7-960 (A major upgrade for me). It's rated at 3.2 GHz and I've read that the FSB speed is 1066 mhz. I've also read that it is compatible with DDR3 800 or DDR3 1066. My question is, should I buy 1066 RAM to match the FSB speed, or should I buy 1333 or 1600 speed with the intent of tightening up the timings? Or, should I buy 1333 or 1600 with the intent of OCing the processor?

More about : cpu ram speed match fsb

July 13, 2011 9:17:53 PM

That depends mostly on what you will be using the machine for. To give you a bit of an idea, here is what I did. (I built my machine about 14 months ago, so things obviously will have changed some.)

I use my computer for work: writing software, word processing, internet, etc. No gaming or things in that line. I have an Intel Core i7 Processor i7-930 2.80GHz 8 MB LGA1366 CPU, and G Skill F3-12800CL7T-6GBPI memory. Just a few days ago I wanted to add more memory, so I went out and bought this memory: G Skill F3-12800CL9T-12GBRL.

If that still doesn't give you some tips or answer your questions, please let me know!
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July 13, 2011 10:33:38 PM

I guess my question really boils down to where will I see the best real world performance? Would matching the memory bandwidth with the FSB be better than say buying faster RAM?
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a c 109 } Memory
July 14, 2011 1:00:33 AM

jellington90 said:
I guess my question really boils down to where will I see the best real world performance? Would matching the memory bandwidth with the FSB be better than say buying faster RAM?



The current Intel nehalem and sandy bridge cpu's have an excellent integrated ram controller.
It is able to keep the cpu fed with data from any speed ram.

The difference in real application performance or FPS between the fastest and slowest ram is on the order of 1-3%.

Synthetic benchmark differences will be impressive, but are largely irrelevant in the real world.


Fancy heat spreaders are mostly marketing too.


Only if you are seeking record level overclocks should you consider faster ram or better latencies.
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July 15, 2011 6:30:25 AM

Thanks. I guess I'll just go with 1066 CL7 to match the bus speed with low latency. It isn't Nehalem or Sandy Bridge, though, it's an older Bloomfield (similar memory controller?).
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July 15, 2011 9:55:04 AM

I would go to your mother board manufaturer website and check out all of the current hardware your Mobo supports.
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a c 109 } Memory
July 15, 2011 3:53:21 PM

You want documented ram compatibility. If you should ever have a problem, you want supported ram.
Otherwise, you risk a finger pointing battle between the ram and motherboard support sites, claiming "not my problem".
One place to check is your motherboards web site.
Look for the ram QVL list. It lists all of the ram kits that have been tested with that particular motherboard.
Sometimes the QVL list is not updated after the motherboard is released.
For more current info, go to a ram vendor's web site and access their ram selection configurator.
Enter your motherboard, and you will get a list of compatible ram kits.
While today's motherboards are more tolerant of different ram, it makes sense to buy ram that is known to work and is supported.

The i7-960 has the nehalem architecture with the integrated ram controller.
You overclock it by adjusting the BCLK.
When you do that, the ram speed will be adjusted also, so it is worthwhile to use ram that will operate at higher speeds without overclocking.
Do not worry about what ram speed gets selected with your oc. It matters little in real application performance.
Fortunately, DDR3-1600 ram is not much more expensive than 1333 or less.
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a c 347 } Memory
July 15, 2011 4:27:53 PM

jellington90 said:
I recently had the fortune to come upon a new quad core Intel Core i7-960

...should I buy 1333 or 1600 speed with the intent of tightening up the timings? Or, ... 1600 with the intent of OCing the processor?

...best real world performance? Would matching the memory bandwidth with the FSB be better than say buying faster RAM?

Damn good Fortune! :)  The i7 9xx craps-out at DDR3 2200.

Get either kit of 3x4GB of DDR3 1600:
$115 3x4GB CORSAIR Vengeance 12GB (3 x 4GB) DDR3 1600 9-9-9-24-2T @ 1.50v Model CMZ12GX3M3A1600C9 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
$135 3x4GB Mushkin Enhanced Blackline 12GB (3 x 4GB) DDR3 1600 8-9-8-24-2T @ 1.60v Model 998989 http://www.newegg.com/Product/Product.aspx?Item=N82E168...

This is the 'best' 3x2GB kit but the 4GB density is being produced more and are currently cheaper.
$129 3x2GB CORSAIR DOMINATOR 6GB (3 x 2GB) DDR3 1600 8-8-8-24-2T @ 1.65v Model TR3X6G1600C8D http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Real World - More GB's of RAM is best, configured in 3x__GB vs the slightly slower 6x__GB, and the DDR3 1600 doesn't require any BCLK (OC) in the vast majority of the X58 MOBO's. Further, the DDR3 1600 improves performance in most every App and adds FPS to the GPU - reason more data can be pushed in a quicker period of time. The 'best' performance is from DDR3 1800 & 2000 BUT requires a BCLK >=160 MHz in other words an OC, and in particular DDR3 2000 is tricky to remain stable. DDR3 1600 is EASY to run.

Keep in mind you MUST set the DRAM Frequency or use XMP in the BIOS to achieve anything faster than the default DDR3 1066. ;) 

Tests:
Comparison Module #1: Mushkin Redline 996805 6-8-6-24 1600MHz
Comparison Module #2: G.Skill Pi Series 7-8-7-24 1600MHz
Comparison Module #3: Mushkin 998687 8-9-8-24 1866MHz
Comparison Module #4: Corsair Dominator TR3X6G1600C8D 8-8-8-24 1600MHz
Comparison Module #5: Kingston HyperX T1 9-9-9-27 1600MHz
Comparison Module #6: Mushkin Blackline 998677B 7-7-7-20 1333MHz
Comparison Module #7: Patriot Viper II Sector 7 9-9-9-27 1800MHz

Stock:


Gaming 1800 MHz:

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July 15, 2011 10:05:04 PM

Great replies guys, thanks. I'll go with 1600 instead to leave some room for increasing CPU speed.
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July 16, 2011 2:52:47 AM

jellington90 said:
Thanks. I guess I'll just go with 1066 CL7 to match the bus speed with low latency. It isn't Nehalem or Sandy Bridge, though, it's an older Bloomfield (similar memory controller?).

Bloomfield is based on the Nehalem micro-architecture.

Enjoy that processor!!

BTW: You need memory at 1.65v or lower DRAM voltage.
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July 17, 2011 3:20:48 AM

sykozis said:
Bloomfield is based on the Nehalem micro-architecture.

Enjoy that processor!!

BTW: You need memory at 1.65v or lower DRAM voltage.


Thanks for the information. I ended up buying 8GB of Kingston HyperX 1600 CL9. It supports XMP and runs at 1.65v. Super excited!

A buddy got his order lost by UPS, so Newegg sent him all new stuff. UPS ended up finding it, and he gave me his order. Got that processor, an Asus Rampage III Extreme mobo, WD 600GB 7000RPM (if I remember off top of head), and a sweet aluminum case. Now that RAM is out of the way just need a PSU and video card. But I think I'm going to use my old stuff until I get some more money.
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a c 347 } Memory
July 17, 2011 1:48:35 PM

IMO - I wouldn't be selecting Dual Channel kits on a Tri Channel MOBO. There's no 'good' way to add an 'odd' stick later. Yes, Dual Channel kits will work.

X58 Configurations:
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July 17, 2011 4:53:08 PM

Unless you're using memory intensive apps, you won't notice the difference between dual and triple channel memory configurations.
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a c 347 } Memory
July 17, 2011 5:04:53 PM

Not arguing speed. Once you add 2x_GB you're stuck to 2x_GB or 4x_GB. One of the primary reasons for X58 vs P55 is RAM the other PCIe along with 6-core CPUs.

-> There's no 'good' way to add an 'odd' stick later.
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July 17, 2011 5:06:35 PM

Would I not be able to put an 'odd' stick in without it trying to run it in triple channel (not working because the stick is different)?

Also, I was planning on buying one more stick of the same stuff when I got some money so hopefully I won't run into this problem.
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a c 109 } Memory
July 17, 2011 5:22:43 PM

jellington90 said:
Would I not be able to put an 'odd' stick in without it trying to run it in triple channel (not working because the stick is different)?

Also, I was planning on buying one more stick of the same stuff when I got some money so hopefully I won't run into this problem.


Compatibility with an odd stick is never guaranteed, but recent motherboards seem to tolerate differences well, so long as the speed and voltage is the same.

If you need only 8gb, (and that is plenty for most of us) stick with what you have, dual channel will not be a problem.

If you need more, get the appropriate number of sticks. If you have >16gb, you will need more than home premium to access the extra ram.

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July 18, 2011 12:52:01 AM

jaquith said:
Not arguing speed. Once you add 2x_GB you're stuck to 2x_GB or 4x_GB. One of the primary reasons for X58 vs P55 is RAM the other PCIe along with 6-core CPUs.

-> There's no 'good' way to add an 'odd' stick later.


How do you figure? Order 1 stick of the same memory and add it. They still sell single sticks of ram.
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a c 347 } Memory
July 18, 2011 2:00:38 AM

RAM at even 'SPD', in the case of LGA 1366, 1066 perhaps IF the CAS Timings are exact matches, but otherwise hodge-podge almost never works at Rated speeds and CAS Timings. I've seen this debate 100+ times and most all were failures.

Frequently, even two sets of matched pairs might not work together in Dual Channel LGA 1155 at Rated speed. Example, F3-12800CL9D-8GBXL one kit has no problem running 1600 but two kits combined very frequently run at 1333 no matter what you try to do.

I'm more into KNOWING the outcome than subjecting my important data to guesses, corruption, failures, etc.

The few bucks savings often end up as a complete waste. While I appreciate a philosophy like @ronjarvis I'm not one to by other's junk; I'm the boss and not the employee and I never buy/sell/trade with my employees.
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July 31, 2011 1:44:57 PM

If you order the exact same ram....it will function, the exact same...
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