What's up with Intel going back to dual channel memory?

**sillyeagle** · 12-15-11, 09:57 PM

I've read at least 5 Sandy Bridge reviews, and none of them touch on why triple channel memory is no longer offered/needed. One review did talk about improvements with pre-fetch, which makes it sound like Sandy Bridge just doesn't need as much bandwidth as Nehalem. Is that right?

I think Nehalem using triple channel has 25% more memory bandwidth than SB, but seems hard to believe pre-fetch improvements alone could lead to SB using 25% less bandwidth.

**Roadhog** · 12-15-11, 10:13 PM

Sandy bridge has way more memory bandwidth than nehalem.

http://www.guru3d.com/article/core-i...600k-review/18

Viral · 12-15-11, 10:40 PM

Who really cares if it has less of something if it still performs better.

**sillyeagle** · 12-15-11, 11:08 PM

Quote:

Originally Posted by Roadhog

Sandy bridge has way more memory bandwidth than nehalem.

http://www.guru3d.com/article/core-i...600k-review/18

Hmm, well the 25% figured I saw was this:

Quote:

Originally Posted by Bit Tech

Triple-channel Nehalem CPUs still provides around 25 per cent more throughput than Sandy Bridge, and the new CPU needs to scale all the way to 2,133MHz in order to exceed Nehalem's 1,600MHz figure.

http://www.bit-tech.net/hardware/mem...andy-bridge/12

Given the figures you posted I'm not sure what bit tech is talking about here. Also I have yet to figure out how SB is running more bandwidth than Nehalem in the guru3d test considering they're only using 1600MHz memory with the SB rig, which I assume is what their Nehalem rig is also using.

Quote:

Originally Posted by Viral

Who really cares if it has less of something if it still performs better.

You have a problem with somebody trying to understanding the reasons why it does or does not perform better? You might enjoy just not worrying about it and remaining ignorant of such things, but I generally like to understand those things when looking at a new system.

**Roadhog** · 12-15-11, 11:49 PM

Yeah, not sure what to tell you. I don't follow SB that much.

**mullet** · 12-16-11, 12:02 AM

I love my dual channel mobo.

**Rakeesh** · 12-16-11, 12:54 AM

I think the better question is, why bother with triple channel memory?

http://www.tomshardware.com/reviews/...m,2057-13.html

Ninja Prime · 12-16-11, 01:52 AM

The short answer is, most of the time, CPUs don't need huge bandwidth to RAM. Triple channel was mostly a waste when it came out, maybe on SB-E it might matter a little, but even then its single digit precentage I'm guessing.

Bah! · 12-16-11, 02:24 AM

Why did they get rid of it? Because it was a useless feature that barely gave any performance increase in synthetic benchmarks and zero increase in actual use.

**sillyeagle** · 12-16-11, 02:54 AM

Yes, thank you. I guess the guru3d results are better simply because the CPU is faster... no memory bottleneck either way. Makes sense.

Ninja Prime · 12-16-11, 03:47 AM

In a multi-chip server/supercomputer board it might have more impact, so thats probably the major reason for the original inclusion.

bobkn · 12-16-11, 08:16 AM

Odd that no one has mentioned:

Intel has gone to quad channel with Socket 2011, and the Sandy Bridge E processors.

http://en.wikipedia.org/wiki/LGA_2011

12-15-11, 09:57 PM	#1
sillyeagle sillyego Join Date: Sep 2005 Location: USA Posts: 5,385	What's up with Intel going back to dual channel memory? I've read at least 5 Sandy Bridge reviews, and none of them touch on why triple channel memory is no longer offered/needed. One review did talk about improvements with pre-fetch, which makes it sound like Sandy Bridge just doesn't need as much bandwidth as Nehalem. Is that right? I think Nehalem using triple channel has 25% more memory bandwidth than SB, but seems hard to believe pre-fetch improvements alone could lead to SB using 25% less bandwidth. __________________ Intel Core i7 920 Nehalem Quad @ 4.0GHz EVGA GTX 660 SLI @ 1046MHz OCZ Platinum CL7 6GB EVGA Intel X58 _____________ A man's dreams are an index to his greatness.

12-15-11, 10:13 PM	#2
Roadhog Resident Alien Join Date: Jan 2005 Posts: 6,776	Re: What's up with Intel going back to dual channel memory? Sandy bridge has way more memory bandwidth than nehalem. http://www.guru3d.com/article/core-i...600k-review/18

12-15-11, 10:40 PM	#3
Viral Registered User of Women Join Date: Aug 2003 Location: Australia Posts: 2,523	Re: What's up with Intel going back to dual channel memory? Who really cares if it has less of something if it still performs better. __________________ Q9550 w/ Thermalright Ultra 120 Extreme \| 4GB Team Xtreme Dark 800MHz CL4 \| Gigabyte X48-DS5 ASUS Radeon 5870 \| 240GB OCZ Vertex 2 \| 1TB WD Green Power \| BenQ V2400W 24" LCD Corsair HX-1000w \| LG GGW-H20L 6x DL Blu-Ray Burner/HD-DVD Reader \| Coolermaster Cosmos S Acer TravelMate 4002WNLCi: Pentium M 725 @ 1.6GHz \| Mobility Radeon 9700/64MB \| 2GB DDR400 \| 15.4" WXGA

12-15-11, 11:49 PM	#5
Roadhog Resident Alien Join Date: Jan 2005 Posts: 6,776	Re: What's up with Intel going back to dual channel memory? Yeah, not sure what to tell you. I don't follow SB that much.

12-16-11, 12:02 AM	#6
mullet Join Date: Oct 2005 Posts: 7,995	Re: What's up with Intel going back to dual channel memory? I love my dual channel mobo. __________________ • LIAN-LI PC-A70B • ASUS MAXIMUS V FORMULA (0701) • i7-3770k + NOCTUA\|NH-D14 • Intel 520 240GB SSD • G.SKILL Ripjaws X Series 16GB DDR3 1600 • • EVGA GeForce GTX 680 • PCP&C 750 Quad • ASUS 12x BD-ROM • DELL U2412M E-IPS • Windows 7 Pro x64 SP1 • Logitech Z5500 5.1 •

12-16-11, 12:54 AM	#7
Rakeesh Join Date: Jun 2004 Location: Sonoran Desert Posts: 6,853	Re: What's up with Intel going back to dual channel memory? I think the better question is, why bother with triple channel memory? http://www.tomshardware.com/reviews/...m,2057-13.html __________________ Want to listen to audio without your computer going to sleep? Try this. Core i7 2600k 4.4Ghz 1.385v \| Corsair H60 \| 8GB Corsair Vengeance 1600 8-8-8-24 \| MSI P67A-G45 \| OCZ Vertex 3 \| Sapphire 7850 OC to Max settings

12-16-11, 01:52 AM	#8
Ninja Prime Registered User Join Date: Mar 2003 Location: Utah Posts: 2,263	Re: What's up with Intel going back to dual channel memory? The short answer is, most of the time, CPUs don't need huge bandwidth to RAM. Triple channel was mostly a waste when it came out, maybe on SB-E it might matter a little, but even then its single digit precentage I'm guessing.

12-16-11, 02:24 AM	#9
Bah! Registered User Join Date: Aug 2002 Posts: 868	Re: What's up with Intel going back to dual channel memory? Why did they get rid of it? Because it was a useless feature that barely gave any performance increase in synthetic benchmarks and zero increase in actual use.

12-16-11, 02:54 AM	#10
sillyeagle sillyego Join Date: Sep 2005 Location: USA Posts: 5,385	Re: What's up with Intel going back to dual channel memory? Yes, thank you. I guess the guru3d results are better simply because the CPU is faster... no memory bottleneck either way. Makes sense. __________________ Intel Core i7 920 Nehalem Quad @ 4.0GHz EVGA GTX 660 SLI @ 1046MHz OCZ Platinum CL7 6GB EVGA Intel X58 _____________ A man's dreams are an index to his greatness.

12-16-11, 03:47 AM	#11
Ninja Prime Registered User Join Date: Mar 2003 Location: Utah Posts: 2,263	Re: What's up with Intel going back to dual channel memory? In a multi-chip server/supercomputer board it might have more impact, so thats probably the major reason for the original inclusion.

12-16-11, 08:16 AM	#12
bobkn Registered User Join Date: Aug 2004 Location: CT USA Posts: 48	Re: What's up with Intel going back to dual channel memory? Odd that no one has mentioned: Intel has gone to quad channel with Socket 2011, and the Sandy Bridge E processors. http://en.wikipedia.org/wiki/LGA_2011 __________________ Intel I7-3930k, Asus P9X79 Pro, nVidia GTX680, Asus PA246Q monitor, 4 X 4 GB g.skill DDR3-2133, Creative X-Fi Titanium, Corsair Force GT 120GB SSD, WD Caviar Black 1.5TB, Win7 X64 Pro