The Secrets of PC Memory: Part 4 - bit-tech.net Forums

Tim S · 10th Feb 2008, 07:40

http://www.bit-tech.net/hardware/200...emory_part_4/1

Carrying on from DDR1 and DDR2 in Part 3, Ryan investigates what makes DDR3 so special, by looking in-depth at its unique features like the Fly-By topology, Read/Write levelling, Dynamic On-Die Termination & ZQ Driver Calibration.

Freedom · 10th Feb 2008, 10:57

Nice article but could you please not call voltage power. Power = current * voltage. So while the voltage may be lower the current they draw is just as important.

noobarino · 10th Feb 2008, 12:14

i agree

wuyanxu · 10th Feb 2008, 12:17

hey, where did that timeline table on page one go? i was going to look at it more closely later.

edit: hum..... it's still not displaying for me

Bindibadgi · 10th Feb 2008, 12:26

Quote:

Originally Posted by wuyanxu

hey, where did that timeline table on page one go? i was going to look at it more closely later.

Uh, it's still there!?

Also, if the voltage drops and the current stays the same, surely the power will drop?

If you (ever) find anything technically inaccurate - feel free to email/PM me

ryanjleng · 10th Feb 2008, 16:59

Quote:

Originally Posted by wuyanxu

hey, where did that timeline table on page one go? i was going to look at it more closely later.

edit: hum..... it's still not displaying for me

You mean this?

That was in Part-3

http://www.bit-tech.net/hardware/200...emory_part_3/1

Kipman725 · 10th Feb 2008, 23:17

the voltage drop reduces power consumption because all transistors and mosfets have an input capacitance and therfore as they are made up of such devices all IC's have input capacitance. If smaller signaling voltages are used this input capacitance has to store and discharge less total energy per voltage transision. This is also why reducing the switching activity (reducing frequancy) reduces power consumption. this is more pronounced when IC's are constrcted using CMOS tech wherby the non switching power consumption is negligable per gate (unless built on a very small proccess wherby quantum tunneling causes problems) (which is why intell gets all excited over new insulators).

basicly lower signaling voltages = lower power consumption almost all the time.

Bluephoenix · 11th Feb 2008, 04:21

Very well written, Good job!

LVMike · 11th Feb 2008, 06:00

I learned a lot about ddr3 i didn't know from this article. I enjoyed it very much, good job.

ChiperSoft · 11th Feb 2008, 16:59

Yeah, this finally explained to me why DDR3 is actually worth using. The simple fact that it can move a whole byte for each clock cycle is pretty awesome.

10th Feb 2008, 07:40	#1
Tim S Pewlius Caesar bit-tech Staff Join Date: Nov 2001 Location: Ascot, Berks Posts: 18,021	The Secrets of PC Memory: Part 4 http://www.bit-tech.net/hardware/200...emory_part_4/1 Carrying on from DDR1 and DDR2 in Part 3, Ryan investigates what makes DDR3 so special, by looking in-depth at its unique features like the Fly-By topology, Read/Write levelling, Dynamic On-Die Termination & ZQ Driver Calibration. __________________ Tim on Twitter \| Tim's Blog \| Tim's Flickr The bit-tech Blog \| bit-tech on Twitter \| Join the bit-tech & Custom PC folding team (#35947)

10th Feb 2008, 12:17	#4
wuyanxu quad fuelled, GTX200 powered Join Date: Aug 2007 Location: in a room near Soton Uni. UK Posts: 3,943	hey, where did that timeline table on page one go? i was going to look at it more closely later. edit: hum..... it's still not displaying for me __________________ Death to consolification !!!Core i7 860 @ 4Ghz Cooled by Corsair H50 // Asus P7P55D Deluxe // 8GB of Corsair Dominators @ 1528Mhz 8-8-8-24 // BFG gtx260+ OC2 MaxCore 216SP 896MB // Samsung 64GB SSD // WD Raptor 74GB + Black 1TB + Green 1TB // Corsair Hx620w // Antec p182 // Samsung 24" T240 Last edited by wuyanxu; 10th Feb 2008 at 12:46.

10th Feb 2008, 23:17	#7
Kipman725 When did I get a custom title!?! Join Date: Nov 2004 Location: UK Posts: 1,753	the voltage drop reduces power consumption because all transistors and mosfets have an input capacitance and therfore as they are made up of such devices all IC's have input capacitance. If smaller signaling voltages are used this input capacitance has to store and discharge less total energy per voltage transision. This is also why reducing the switching activity (reducing frequancy) reduces power consumption. this is more pronounced when IC's are constrcted using CMOS tech wherby the non switching power consumption is negligable per gate (unless built on a very small proccess wherby quantum tunneling causes problems) (which is why intell gets all excited over new insulators). basicly lower signaling voltages = lower power consumption almost all the time. __________________ Sn45g game server mod My Electronics Site Hardware: 3400+ Sempr0n, 1GB RAM, 1.28TB local storage, x1950pro,Razer Viper,M$ comfort curve 2000,L70S + 17", Fujitsu 17" CRT Audio: HD-650's, PE congress amp, Sound Blaster AWE64, Soundblaster 24bit

10th Feb 2008, 10:57	#2
Freedom Hypermodder Join Date: Oct 2004 Location: Manchester England Posts: 603	Nice article but could you please not call voltage power. Power = current * voltage. So while the voltage may be lower the current they draw is just as important.

10th Feb 2008, 12:14	#3
noobarino Minimodder Join Date: Aug 2007 Posts: 33	i agree

11th Feb 2008, 04:21	#8
Bluephoenix Spoon? What spoon? Join Date: Dec 2006 Location: Daytona Beach, FL Posts: 936	Very well written, Good job!

11th Feb 2008, 06:00	#9
LVMike Supermodder Join Date: Aug 2004 Location: Las Vegas NV & Rolla MO Posts: 412	I learned a lot about ddr3 i didn't know from this article. I enjoyed it very much, good job.

11th Feb 2008, 16:59	#10
ChiperSoft Minimodder Join Date: Aug 2006 Location: San Diego, CA, USA Posts: 46	Yeah, this finally explained to me why DDR3 is actually worth using. The simple fact that it can move a whole byte for each clock cycle is pretty awesome.