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Cas latency and voltage (G.Skill)

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March 30, 2012 11:57:54 AM

Are there any significant differences with these memory kits? Other than the heat spreaders? From what I understand, lower cas latency will show up in benchmarks but not much in the real world. So with 4 x 4GB with all my RAM slots filled is there a benefit to 1.35v vs 1.5v? Bottom line - should I get one with lower cas latency or lower voltage? Or, the one that ends in 2N (What does that mean???) e.g. 9-9-9-24-2N
Thanks

Asus P8Z68V-PRO/GEN 3 with i7 2600K with XIGMATEK Gaia SD1283

http://www.newegg.com/Product/ProductList.aspx?Submit=E...
a c 347 } Memory
March 30, 2012 12:50:34 PM

In performance both Frequency and CAS are equally important, the limitations are in the CPU and CPU's IMC. The 1.35v kits are better for the CPU and reduce the burden to the CPU's IMC. The 2N aka Command Rate (CMD) is the Delay between chip select and command, or the number of clock cycles needed to send data.

Most folks don't know how to properly configure 1.35v RAM, but I prefer it over 1.50v on the Sandy Bridge. However, other than being easier on the IMC it won't aide in performance. Furthermore, if all your doing is gaming then only under rare circumstances will 2x4GB vs 4x4GB offer any advantages whatsoever, and since running 2xDIMM per channel is slightly less efficient it's actually slower.

Gaming I recommend 2x4GB DDR3-1600 CAS 8/9 memory, and if you OC 2x4GB DDR3-1866 CAS 9. Nice article - http://www.bit-tech.net/hardware/memory/2011/01/11/the-...

Rendering I recommend as much memory as you can reasonably afford, and clearly 4x4GB is the cheapest and clear does offer an advantage over less RAM. Rendering 4x4GB DDR3-1600 CAS 8/9 memory, faster might help but stability is more important.

Kits I recommend (in keeping with theme) - http://www.newegg.com/Product/Productcompare.aspx?Submi...
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April 1, 2012 8:26:54 AM

jaquith said:
In performance both Frequency and CAS are equally important, the limitations are in the CPU and CPU's IMC. The 1.35v kits are better for the CPU and reduce the burden to the CPU's IMC. The 2N aka Command Rate (CMD) is the Delay between chip select and command, or the number of clock cycles needed to send data.

Most folks don't know how to properly configure 1.35v RAM, but I prefer it over 1.50v on the Sandy Bridge. However, other than being easier on the IMC it won't aide in performance. Furthermore, if all your doing is gaming then only under rare circumstances will 2x4GB vs 4x4GB offer any advantages whatsoever, and since running 2xDIMM per channel is slightly less efficient it's actually slower.

Gaming I recommend 2x4GB DDR3-1600 CAS 8/9 memory, and if you OC 2x4GB DDR3-1866 CAS 9. Nice article - http://www.bit-tech.net/hardware/memory/2011/01/11/the-...

Rendering I recommend as much memory as you can reasonably afford, and clearly 4x4GB is the cheapest and clear does offer an advantage over less RAM. Rendering 4x4GB DDR3-1600 CAS 8/9 memory, faster might help but stability is more important.

Kits I recommend (in keeping with theme) - http://www.newegg.com/Product/Productcompare.aspx?Submi...


Thanks. I should have mentioned that I'm not a gamer (might get interested in the future). Mostly work with photos and videos plus everyday general use. More speed is nice but stability is more important to me. I think 4 x 4GB 1.35v would be a good choice. You mentioned proper configuration of the 1.35v - can you suggest any good articles to assist me with proper configuation? (And that you don't have to be a rocket scientist to understand :D  )
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a c 347 } Memory
April 1, 2012 3:13:08 PM

Here's a problem, the e.g. Ares F3-12800CL9Q-16GBXM recommends a VCCSA (VCCIO) of 1.25v, and I really don't recommend you exceed 1.20v. So IMO look for a different 1.35v kit (non-Ares). Most of the 16GB kits are tested with a VCCSA (VCCIO) of 1.10v at the manufacture.

Most of the articles/posts are going to be from me anyway...

So lets say:
RAM: F3-12800CL9Q-16GBXM G.SKILL ; DDR3-1600 9-9-9-24-2N @ 1.35v
MOBO: ASUS P8Z68-V PRO/GEN3

BIOS Options:

XMP Method:
AI Overclock Tuner -> XMP
VCCIO Voltage -> 1.10v ; 1.15v only if needed i.e. unstable
DRAM Voltage -> 1.35v ; 1.38v only if needed i.e. unstable ; set manually if OC the CPU
Save & Exit = Yes

Manual Method:
AI Overclock Tuner -> Manual
DRAM Memory Frequency -> DDR3-1600
DRAM Timing Control /Enter
DRAM CAS -> 9
DRAM RAS to CAS -> 9
DRAM RAS PRE -> 9
DRAM RAS ACY -> 24
DRAM Command Mode -> 2

VCCIO Voltage -> 1.10v ; 1.15v only if needed i.e. unstable
DRAM Voltage -> 1.35v ; 1.38v only if needed i.e. unstable ; set manually if OC the CPU
Save & Exit = Yes

Hope that helps! :) 
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April 2, 2012 6:15:47 PM

jaquith said:
Here's a problem, the e.g. Ares F3-12800CL9Q-16GBXM recommends a VCCSA (VCCIO) of 1.25v, and I really don't recommend you exceed 1.20v. So IMO look for a different 1.35v kit (non-Ares). Most of the 16GB kits are tested with a VCCSA (VCCIO) of 1.10v at the manufacture.

Most of the articles/posts are going to be from me anyway...

So lets say:
RAM: F3-12800CL9Q-16GBXM G.SKILL ; DDR3-1600 9-9-9-24-2N @ 1.35v
MOBO: ASUS P8Z68-V PRO/GEN3

BIOS Options:

XMP Method:
AI Overclock Tuner -> XMP
VCCIO Voltage -> 1.10v ; 1.15v only if needed i.e. unstable
DRAM Voltage -> 1.35v ; 1.38v only if needed i.e. unstable ; set manually if OC the CPU
Save & Exit = Yes

Manual Method:
AI Overclock Tuner -> Manual
DRAM Memory Frequency -> DDR3-1600
DRAM Timing Control /Enter
DRAM CAS -> 9
DRAM RAS to CAS -> 9
DRAM RAS PRE -> 9
DRAM RAS ACY -> 24
DRAM Command Mode -> 2

VCCIO Voltage -> 1.10v ; 1.15v only if needed i.e. unstable
DRAM Voltage -> 1.35v ; 1.38v only if needed i.e. unstable ; set manually if OC the CPU
Save & Exit = Yes

Hope that helps! :) 



Ahhh, OK. Thanks for your time. I researched VCCIO and have a basic understanding of what that is now. The 2 kits I'm looking at are:

G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model F3-12800CL9Q-16GBXM
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

G.SKILL Sniper Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model F3-12800CL9Q-16GBSR1
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

The specs appear identical, the only difference seems to be the heat spreaders on the Ripjaws vs the Sniper which appears more low-profile. I like the Ripjaws X and think I will get a Kuhler 620 instead of the Xigmatek so clearance for the heat spreaders won't be an issue. (should also run more quietly)
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a c 347 } Memory
April 2, 2012 6:23:43 PM

Lower voltage are best on the CPU and the CPU's IMC. Remember or know, DDR3-1600 @ either 1.50v or 1.35v are not going to be anything but warm especially 4GB/stick densities.

Either fit underneath any HSF that I can think of and the Kuhler 620 clearly height is irrelevant.
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April 10, 2012 3:27:55 PM

Best answer selected by nodellsplease.
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a c 146 } Memory
April 11, 2012 1:53:26 AM

This topic has been closed by Nikorr
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