Quad channel ram?

[PP Mguire]

According to this my buddy is running quad channel ram.

Quad would be 256bit right?
So if this is the case why is Nehalem triple channel and not native quad channel for one cpu?

Or is there something that im missing that needs to be said here.
I thought it was because he had 2 cpus that are both dual core. So 2x 2 dual channel controlers would be "quad pumped" not sought as "quad channel/256bit"

Explain?

 

[zithe]

I'm confused too. You'd think the memory and the board would also need to be developed to run in 'quad channel'.

 

[hbkl]

well im more confused than yours xD

 

[Disparia]

I'm confused too. You'd think the memory and the board would also need to be developed to run in 'quad channel'.

5000x chipset - it is developed for quad channel memory

 

[zithe]

5000x chipset - it is developed for quad channel memory

That's a start. Now is there quad channel memory available yet?

 

[PP Mguire]

This is a server board, server FB ram, and 2 server Xeons (obviously).

So its really quad channel? Cause if so im gonna feel like the biggest n00b ever.

 

[ntdouglas]

He's running 8 gig at ddr2-533. Where's the timings at under the cpuz memory tab? And the channels box is greyed out. So no, he's not in duel channel either. What board is he running?

 

[PP Mguire]

It says it in CPU-Z. Its a Dell server system that he stuffed some SCSI Cheetahs in and an 8800GT. He set the world record for that cpu at 2.6ghz as well.

 

[Disparia]

This is a server board, server FB ram, and 2 server Xeons (obviously).

So its really quad channel? Cause if so im gonna feel like the biggest n00b ever.

The successor is the 5300 series of chipsets, supporting quad FB DDR2-800.

-edit- ^5400

 

[PP Mguire]

I see. Well i spotted something horrible. 256bit memory interface but only a 64bit FSB. Thats like taking an interstate highway during rush hour and making it 2 lanes.

 

[ntdouglas]

It says it in CPU-Z. Its a Dell server system that he stuffed some SCSI Cheetahs in and an 8800GT. He set the world record for that cpu at 2.6ghz as well.

Sorry, didn't see it was a server board. Just focusing on the ram. Not quite sure about the quad channel thing. Cpuz must not support that board then.

 

[Mussels]

yeah its a server board with quad channel ram. the MHz and latencies are usually pretty poor for that kinda system however.

 

[CrAsHnBuRnXp]

Quad channel is only Dual channel *2. A G.Skill rep told me cause I asked abotu this on another fourm. Heres the link.

http://www.eggxpert.com/forums/thread/164031.aspx

actually it is dual channel *2, not real quad channel

with the quad channel pack, we test the four sticks at the same time to avoid incompatibility

because not every two sets of dual channel kit can run together without any problem, we announced this quad channel pack

If there is performance difference between dual channel and "quad channel,"
it should be caused by larger capacity, not "quad channel"

there is no such real quad channel now, they are still dual channel

the "quad channel" we call now is just four sticks which can run together

 

[Mussels]

the Gskill guy wont be talking about FBdimms in a server environment... he'd be talking about 4x1 or 4x2GB packs of ram

 

[PP Mguire]

That guys isnt talking about the same thing we are though.

 

[lemonadesoda]

Your friend is running Quad Channel. Some server and workstation boards can also run Octochannel. You need the very expensive chipsets to do this. Memory bandwidth pwns a regular "consumer" mainboard. But FB-DIMMs are required: expensive and power hungry.

LOL@CrAsHnBuRnXp. The guy is refering to RAM kits, no capabilities of a mainboard.

Skulltrail is the nearest thing an "enthusiast" gets to specialist workstation performance: http://en.wikipedia.org/wiki/Intel_SkullTrail

Intel chipset 5400 allows for 800 clocked FBDIMMs. The older 5100 chipset only has 533 memory IIRC

http://www.asus.com/products.aspx?l1=3&l2=82&l3=644&l4=0&model=2090&modelmenu=1

 

[Mussels]

thanks lemonade, well written post explaining the situation better than i did.

 

[Deleted member 3]

It says it in CPU-Z. Its a Dell server system that he stuffed some SCSI Cheetahs in and an 8800GT. He set the world record for that cpu at 2.6ghz as well.

It's a crap CPU though. And considering the chipset won't go past ~390MHz 2.6GHz won't happen.

The successor is the 5300 series of chipsets, supporting quad FB DDR2-800.

There is no 5300 series. There is the 5400 Seaburg and the budget variation 5100. (uses reg DDR2 instead of FB)

That's a start. Now is there quad channel memory available yet?

Channels are a chipset feature, not a memory feature. As far as the memory is concerned you can run it in 100 channel configurations.

I see. Well i spotted something horrible. 256bit memory interface but only a 64bit FSB. Thats like taking an interstate highway during rush hour and making it 2 lanes.

Funny fact, the memory performs worse than dual channel DDR2. There are two FSB's, ie 2x 64bit. The memory is bottlenecking, not the FSB.

He's running 8 gig at ddr2-533. Where's the timings at under the cpuz memory tab? And the channels box is greyed out. So no, he's not in duel channel either. What board is he running?

Timings are pretty much set for FB-DIMM's, latency is mostly cause by the AMB though. It's usually in the 80-100 area, pretty poor.

 

[Deleted member 3]

Your friend is running Quad Channel. Some server and workstation boards can also run Octochannel. You need the very expensive chipsets to do this. Memory bandwidth pwns a regular "consumer" mainboard. But FB-DIMMs are required: expensive and power hungry.

Care to give me a source for that? I've never heard of these boards. Also, I've never seen FB-DIMMs pwn anything, a source for that would be interesting as well.

Intel chipset 5400 allows for 800 clocked FBDIMMs. The older 5100 chipset only has 533 memory IIRC

The 5100 isn't older, it's Seaburgs budget brother, same generation.

 

[btarunr]

The older chipset is 5000 V/P/X.

 

[lemonadesoda]

1./ FB-DIMMs "drink"!

2./ For Dan, http://en.wikipedia.org/wiki/UltraSPARC_T2. 4 independent FB-DIMM dual channel controllers = octochannel

3./ I had understood that the slower 5100 chipset with max FSB 333 was older than 5400 FSB 400. But perhaps as Dan suggested, it is the same generation, just came out first, slower, and cheaper?

4./ FB-DIMM has a "rank" concept. Adding more memory to "ranks" of the same channel increases bandwidth. I think Dan would be able to explain the FB-DIMM technology better than me. But here's a link or two that explain, but infortunately, without real word benchmarking http://download.micron.com/pdf/techn...dr2/tn4721.pdf http://www.simmtester.com/PAGE/news/showpubnews.asp?where=533424&num=136

5./ Bandwidth on fully populated FB-DIMM server chipset pwns a regular dual channel DDR. Why? Quad channel vs. 2 channel, PLUS 2 rank vs. single, PLUS FB-DIMM allows SIMULTANEOUS read and write. Regular DDR cannot do this. Big gains when multitasking and/or tasking with mix read/write. But latencies on regular DDR are lower. Swings and roundabouts depending on purpose.

NOTE >> Most reviewers who have tested bandwidth of FB-DIMM make the FATAL FLAW of using only 2 sticks. For max speed you need 8 sticks (4 channels populated, 2 ranks each). Plus, to see the real benefit you need to compare read/wriet benchmarks not just simplistic read only or write only. If anyone has a benchie or wants to hunt one down on the net... please link.


PERSONAL BET >> I'm pretty sure a xeon on quad channel FB-DIMM (2 rank even better) completing a video encoding task, e.g. MPEG2 to DIVX, would STOMP a similar Conroe DDR2 setup same clocks.

 

[Deleted member 3]

1./ For Dan, http://en.wikipedia.org/wiki/UltraSPARC_T2. 4 independent FB-DIMM dual channel controllers = octochannel

They are four separate controllers according to that text. I would imagine each two cores have their own controller, similar to how many servers have a memory interface per CPU. Look at high end Opteron boards for example. Those aren't quad/octo channel controllers, they simple have a controller per CPU.
The FB-DIMM specs allow six channels per controller, as far as I know there aren't any chipsets utilizing that though.
Anyway, I was assuming we were at least talking about x86 hardware, nobody has a modern Sparc at home.

2./ I had understood that the slower 5100 chipset with max FSB 333 was older than 5400 FSB 400. But perhaps as Dan suggested, it is the same generation, just slower, cheaper and lower power consumption, for blades?

Not per se for blades, though considering the 5100/5400 can waste quite some energy it might not be a bad plan to go for 5100 based blades.

3./ FB-DIMM has a "rank" concept. Adding more memory to "ranks" of the same channel increases bandwidth. I think Dan would be able to explain the FB-DIMM technology better than me. I've never seen it, but Dan's got a nice machine using it. He's the expert.

Most 1GB+ dimms are double rank modules in the first place. I've seen Wintec 4 rank modules as well. Look up some random post I made about ranks and quad channel with 6 modules. The ranks make this possible, same as dual channel with three modules.

4./ Bandwidth on fully populated FB-DIMM server chipset pwns a regular dual channel DDR. But latencies on regular DDR are lower. Swings and roundabouts depending on purpose.


NOTE >> Most reviewers who have tested bandwidth of FB-DIMM make the FATAL FLAW of using only 2 sticks. For max speed you need 4 sticks, ie. 4x 1GB >> 2x 2GB so that all channels are working. Even better to use 8 sticks so you have all channels are 2 ranks. If anyone has a benchie or wants to hunt one down on the net... please link.

Yes, it's a fatal flaw. However, I still haven't seen any impressive numbers coming from FB-DIMMs, perhaps it is better when using 8 modules per channel with 4 rank modules. But this will be quite expensive and use a lot of power.
Besides, my boards only have 6 DIMM slots (and just four on my server) so it's no option for me. I could eventually add two 4GB 4 rank modules though, that way I'd have 4 ranks per channel. (and 16GB of RAM, why would I want that?)

 

[lemonadesoda]

I agree, FB-DIMM is not a winner for any price/performance or power/performance ratio. But, on the simple question about which is faster, for a single threaded test, serial memory benchmark, regular DIMMs will win. But for multi-tasking mixed read/write, FB-DIMM wins.

> Games - DIMM
> Encoding, servers - FB-DIMM (but at a high price)

Academic study http://www.eng.umd.edu/~blj/papers/hpca2007.pdf

Decent, comparable, benchmarks of DDR2 vs. FB-DIMM, same processor family and clock, are IMPOSSIBLE to find :-(

 

[btarunr]

Is this "oct-channel" ?

 

[wolf2009]

^^ WOW , what motherboard is that ? I'm sure its for a server, but how would it perform in video encoding and games ?