Take a look at our
ThinkPads.com HOME PAGE
For those who might want to contribute to the blog, start here: Editors Alley Topic
Then contact Bill with a Private Message

QUESTION: PC2700 vs PC3200 RAM

T4x series specific matters only
Post Reply
Junior Member
Junior Member
Posts: 459
Joined: Thu Sep 20, 2007 11:14 pm
Location: Crossville, TN USA

QUESTION: PC2700 vs PC3200 RAM

#1 Post by sojourner » Sun Dec 06, 2009 2:00 pm

Does anyone know if a T41 can take advantage of greater FSB speeds possible with PC3200 compared with PC2700?

IBM Thinkpad T41 Home | X31 Travel | X60 fun
2GHz Dothan (X60 C2D, X31 1.7 Banias), 2GB RAM, 320GB HDD, DVD Multi-Burner, IBM 11b/g, Bluetooth II, Docks
multi-boot (98SE, W2K, XP PRO, Win7, Linux Mint 10)

Posts: 7865
Joined: Sat Oct 29, 2005 6:20 am
Location: Israel

Re: QUESTION: PC2700 vs PC3200 RAM

#2 Post by dr_st » Sun Dec 06, 2009 3:04 pm

It can't.
Thinkpad 25 (20K7), X1 Carbon (20HQ), Yoga 14 (20FY), T430s (IPS FHD + Classic Keyboard), X220 4291-4BG
X61 7673-V2V, T60 2007-QPG, T42 2373-F7G, X32 (IPS Screen), A31p w/ Ultrabay Numpad, A21m 2628-GXU

Bruce Guttman
Junior Member
Junior Member
Posts: 260
Joined: Wed Apr 21, 2004 11:18 am
Location: New Hampshire, USA

Re: QUESTION: PC2700 vs PC3200 RAM

#3 Post by Bruce Guttman » Thu Dec 10, 2009 5:29 pm

Similar question: I know it won't run faster, but can I put in two PC-3200 sticks and have it work? I know the R-40 is supposed to use PC-2100 sticks but IBM now recommends PC-2700 (like the T-4x series). Does a PC-3200 (NOT PC2-3200) work?
Bruce Guttman

Current stable: 770Z, 600X, T23, R40, R52, T43p, X41, R60, T60, T61, X61, X61T, X201T, T420; T400 (2768-EK9); W510 (4391-CTO), X220T (4296-2W5), T440 (20B6-00AUS), plus an Intellistation M 6219.
New Project: Making X220 work with WWAN.

Admin Emeritus
Admin Emeritus
Posts: 19953
Joined: Mon Sep 18, 2006 5:17 am
Location: Dublin, Ireland

Re: QUESTION: PC2700 vs PC3200 RAM

#4 Post by RealBlackStuff » Thu Dec 10, 2009 6:14 pm

All those RAM modules are (supposed to be) backwards compatible. A 3200 will work in a 2700 and most likely also in a 2100.
A 2700 will work in a 2100 (and a 3200).
They will run at the speed as defined by the onboard-chipset.
So a 2700 will work at 2100 in a 2100 machine, etc.
Lovely day for a Guinness! (the Real Black Stuff). And pigs CAN fly!

Senior Member
Senior Member
Posts: 502
Joined: Wed Oct 19, 2005 3:10 am
Location: Bucharest, Romania, EU

Re: QUESTION: PC2700 vs PC3200 RAM

#5 Post by AIX » Fri Dec 11, 2009 2:38 am

They are supoosed to work but sometimes they are not working; so, to be sure, you have to test it first if possible.
T430 · i7-3632QM · 12GB RAM · 512GB SSD · HD+ · NVIDIA NVS 5400M · H5321gw
T420s · i5-2520M · 12GB RAM · 480GB SSD · HD+ · HD3000 · F5521gw
T60 · T2500 · 3GB RAM · 128GB SSD · 14.1 SXGA+ · 128MB ATI X1400
Past: T400, T41, T22, 600X, 390X

Freshman Member
Posts: 53
Joined: Thu Apr 23, 2009 11:27 pm
Location: Hollywood, FL

Re: QUESTION: PC2700 vs PC3200 RAM

#6 Post by laboye » Sat Dec 12, 2009 5:06 pm

In this situation (PC2100 TP w/ PC2700/PC3200 RAM), I usually get problems only if I mix 2 different brand modules. AFAIK, the problem lies the adjustment of the CAS latency when the module is being slowed down. For example, A PC2100 module might operate with a CAS latency of 2ms while a PC2700 or PC3200 module may have a CAS latency of 3ms. When faster modules are slowed down, they reduce their latency to compensate for the drop in bandwidth. Typically, those faster modules will not operate at 3ms if they are slowed down to PC2100 speed. Some of those 3ms modules will drop to 2ms, but others will drop to 1.5ms. If these 2 differently timed modules are in the same system, it will not start.

In short: Are you using 2 different brands/models of DDR modules?
Personal: T42 2373-K3U (General Purpose);X21 2662-6MU with 2361 dock (Media Handler);Transnote 2675-21U (Um...Transnote!)
Past Personal and Serviced: 240, 570, 600E, A20m, T20, T21, 3x T30, 12xT4x, T43p (I miss it! :(), X20, X24
Current Workbench: X40, 2xX41, 2xT40, 3xT42, 5xiSeries,9x600/E/X

Senior ThinkPadder
Senior ThinkPadder
Posts: 2908
Joined: Tue Jan 22, 2008 8:29 pm
Location: San Jose, CA

Re: QUESTION: PC2700 vs PC3200 RAM

#7 Post by sjthinkpader » Sat Dec 12, 2009 10:51 pm

CAS latency is counted in cycles rather than time.

CAS latency change is not related to drop in bandwidth but the time to get data from storage node to the output buffer doesn't change so much. So at faster (shorter) clock cycles, the RAM needed more clock cycles to get the data to the output buffer. They all need roughly about 12-15 nSec from CAS (column address available) to data on the output buffer. Basically the RAM has to decode the column address, activate the column driver, sense the storage node, drive the output high or low within this period of time. Speed only get faster when the process design rule get smaller or working voltage get lower (such as DDR2, DDR3).

The computer operates at JEDEC standard timing or what the SPD data tells it. If you have two modules of different speed, the data may disappear from the RAM output buffer in one module faster than the computer expects it. This is called not enough HOLD time. If the RAM couldn't get the data there by the time the computer expects it, this is called not enough SETUP time.
T60p 2623-DDU/UXGA IPS/ATI V5200
T60 2623-DCU/SXGA+ IPS/ATI X1400
T43p 2668-H8U/UXGA IPS/ATI V3200
R50p 1832-NU1/UXGA IPS/ATI FireGL T2
X61t 7762-B6U dual touch IPS/64GB SSD
X32 2673-BU6/32GB SSD
755CDV 9545-GBK Transmissive Projection LCD

Post Reply
  • Similar Topics
    Last post

Return to “ThinkPad T4x Series”

Who is online

Users browsing this forum: No registered users and 18 guests