Mixing Different DDR2 Memory

*C0deKing* · 01-02-2007

I have a notebook with a DDR2 533MHz CL4 memory module and a spare DDR2 667MHz CL5 memory module. If I mix the DDR2 533MHz CL4 memory module with a DDR2 667MHz CL5 memory module will they both be forced to run at 533MHz CL5, which will mean the entire memory will be slower?

*DiiZzY* · 01-02-2007

You are aware that your laptop uses SO-DIMM and not just DIMM right?
//Danne

johnnydavidson · 01-02-2007

IMO you will only run as fast as the slowest.

*TimC* · 01-02-2007

Quote:

Originally Posted by johnnydavidson

IMO you will only run as fast as the slowest.

That's the usual outcome.

MetalSlayerX · 01-02-2007

Mixing memories will force the computer to default to the slowest ram speed. It's usually not a good idea when you're trying to run dual channel.

*C0deKing* · 01-02-2007

Thanks guys.

That's what I thought but I wasn't sure the slower CAS Latency would override the other module as well.

Cressida · 01-02-2007

The 667/CL5 module should be able to run at 533/CL4 timing as well. Trouble is you probably won't be able to force it in a notebook BIOS. The cpu-z utility will show you what's happening (maybe with the original 533/CL4 in slot #1 they'll both run like that).

*C0deKing* · 01-02-2007

Quote:

Originally Posted by Cressida

The 667/CL5 module should be able to run at 533/CL4 timing as well. Trouble is you probably won't be able to force it in a notebook BIOS. The cpu-z utility will show you what's happening (maybe with the original 533/CL4 in slot #1 they'll both run like that).

Thanks, yes, that's what I was hoping might happen, but the 667/CL5 module I have is sealed and even though it's a hassle and a cost, I do have an option to exchange it.

*Matth* · 01-02-2007

It's possible the module may have multiple timings, not sure if DDR2 works the same way, but I've seen PC3200 that has 3 timings, CL3 @ 200MHz, CL2.5 @ 166MHz & CL2 @ 133MHz.

Might get away with forcing 533/CL4 if you have manual timings, but the worst case would be the slowest of both speed & timings - if the module does have multiple timings, but they are not correctly recognized, then you may still need a manual setting option (often concealed in OEM BIOSes) in order to enforce the optimal settings

*C0deKing* · 02-02-2007

Yes DDR2 can have multiple timings. The supplier of the memory module has said to try it and see what happen, as they are all out of 533/CL4 sodimm anyway and don't expect to get any more.

Cressida, thanks for reminding me about CPU-Z. I'll check it out later today and see what it says before and after fitting the module. I'll report back as to how I get on.

*C0deKing* · 02-02-2007

It all went well. The 667/CL5 module had a timing table entry for 533/CL4 and it was just selected by default. The only difference is a change in Tras from 11 to 12.

Here's the CPU-Z screen shots, before and after:

Cressida · 02-02-2007

Looks about right there. Glad I could be of help for a change.

Cavalyr · 02-02-2007

wow..glad that worked out dandy for ya..most nice.

01-02-2007	#2
DiiZzY MyCE Resident Join Date: Feb 2004 Location: Nordic Region, Sweden Posts: 3,676	Re: Mixing Different DDR2 Memory You are aware that your laptop uses SO-DIMM and not just DIMM right? //Danne

01-02-2007	#3
johnnydavidson MyCE Senior Member Join Date: Feb 2005 Posts: 352	Re: Mixing Different DDR2 Memory IMO you will only run as fast as the slowest. __________________ 5 AMD and 1 Intel and rising

01-02-2007	#5
MetalSlayerX MyCE Member Join Date: Oct 2005 Posts: 241	Re: Mixing Different DDR2 Memory Mixing memories will force the computer to default to the slowest ram speed. It's usually not a good idea when you're trying to run dual channel. __________________ We are not mind readers, we can't help you if we don't know exactly what you are trying to do. My PC: Windows Vista Ultimate Retail \| Intel E6600 Retail \| Intel 975XBX2 [Bios 2674] Motherboard Retail \| 4GB OCZ FLexXLC DDR2 PC 6400 Retail 4-4-4-15 Timings \| HIS X1950XTX 512MB (stole this from my bro lol) Retail \| Dell 2007FP 20.1" Monitor 1600x1200 \| Thermaltake 750W PSU \| Lian Li Silver PC-68 USB Case Plextor 716-SA April 2005 2yrs Old \| Plextor Premium April 2005 2yrs Old Drive is laying around somewhere \| LiteOn LH-20A1H December 2006 Good Scanner/Okay Burner \| Samsung SH-S183L February 2006 Good Scanner/Solid Burns \| LG GSA-H42N February 2006 Can't Scan/Solid Burns

01-02-2007	#6
C0deKing Retired Senior Administrator Join Date: Mar 2004 Location: In the pack Posts: 11,906	Re: Mixing Different DDR2 Memory Thanks guys. That's what I thought but I wasn't sure the slower CAS Latency would override the other module as well. __________________ http://codeguys.rpc1.org/ LiteOn Tools: EEPROM Utility <-- New v6.2.0, Flash Utility <-- New v6.0.1, Settings Utility <-- New v1.2.1 Samsung Tools: Patch Utility <-- New v3.4.10 LiteOn Patches: Fast Read (FR) \| Fast Burn (FB) \| Enhanced OverSpeed (EOS) \| Enhanced Online HyperTuning (EOHT) BenQ Patches: Fast Burn (FB) \| Enhanced SolidBurn (ESB) Samsung Patches: Fast Read (FR) \| Remove RipLock (RLR) \| Fast Burn (FB) \| Retain book type (BS) \| Default DVD-ROM (ROMD) The man who does things makes mistakes, but he who doesn't makes the biggest mistake of all - doing nothing. Benjamin Franklin The Forum Rules Click HERE to join cdfreaks.com

01-02-2007	#7
Cressida CE Freak Join Date: Mar 2006 Location: Almost there Posts: 4,443	Re: Mixing Different DDR2 Memory The 667/CL5 module should be able to run at 533/CL4 timing as well. Trouble is you probably won't be able to force it in a notebook BIOS. The cpu-z utility will show you what's happening (maybe with the original 533/CL4 in slot #1 they'll both run like that).

01-02-2007	#1
C0deKing Retired Senior Administrator Join Date: Mar 2004 Location: In the pack Posts: 11,906	Mixing Different DDR2 Memory I have a notebook with a DDR2 533MHz CL4 memory module and a spare DDR2 667MHz CL5 memory module. If I mix the DDR2 533MHz CL4 memory module with a DDR2 667MHz CL5 memory module will they both be forced to run at 533MHz CL5, which will mean the entire memory will be slower? __________________ http://codeguys.rpc1.org/ LiteOn Tools: EEPROM Utility <-- New v6.2.0, Flash Utility <-- New v6.0.1, Settings Utility <-- New v1.2.1 Samsung Tools: Patch Utility <-- New v3.4.10 LiteOn Patches: Fast Read (FR) \| Fast Burn (FB) \| Enhanced OverSpeed (EOS) \| Enhanced Online HyperTuning (EOHT) BenQ Patches: Fast Burn (FB) \| Enhanced SolidBurn (ESB) Samsung Patches: Fast Read (FR) \| Remove RipLock (RLR) \| Fast Burn (FB) \| Retain book type (BS) \| Default DVD-ROM (ROMD) The man who does things makes mistakes, but he who doesn't makes the biggest mistake of all - doing nothing. Benjamin Franklin The Forum Rules Click HERE to join cdfreaks.com

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01-02-2007	#9
Matth MyCE Resident Join Date: Aug 2004 Posts: 1,676	Re: Mixing Different DDR2 Memory It's possible the module may have multiple timings, not sure if DDR2 works the same way, but I've seen PC3200 that has 3 timings, CL3 @ 200MHz, CL2.5 @ 166MHz & CL2 @ 133MHz. Might get away with forcing 533/CL4 if you have manual timings, but the worst case would be the slowest of both speed & timings - if the module does have multiple timings, but they are not correctly recognized, then you may still need a manual setting option (often concealed in OEM BIOSes) in order to enforce the optimal settings

02-02-2007	#10
C0deKing Retired Senior Administrator Join Date: Mar 2004 Location: In the pack Posts: 11,906	Re: Mixing Different DDR2 Memory Yes DDR2 can have multiple timings. The supplier of the memory module has said to try it and see what happen, as they are all out of 533/CL4 sodimm anyway and don't expect to get any more. Cressida, thanks for reminding me about CPU-Z. I'll check it out later today and see what it says before and after fitting the module. I'll report back as to how I get on. __________________ http://codeguys.rpc1.org/ LiteOn Tools: EEPROM Utility <-- New v6.2.0, Flash Utility <-- New v6.0.1, Settings Utility <-- New v1.2.1 Samsung Tools: Patch Utility <-- New v3.4.10 LiteOn Patches: Fast Read (FR) \| Fast Burn (FB) \| Enhanced OverSpeed (EOS) \| Enhanced Online HyperTuning (EOHT) BenQ Patches: Fast Burn (FB) \| Enhanced SolidBurn (ESB) Samsung Patches: Fast Read (FR) \| Remove RipLock (RLR) \| Fast Burn (FB) \| Retain book type (BS) \| Default DVD-ROM (ROMD) The man who does things makes mistakes, but he who doesn't makes the biggest mistake of all - doing nothing. Benjamin Franklin The Forum Rules Click HERE to join cdfreaks.com

02-02-2007	#12
Cressida CE Freak Join Date: Mar 2006 Location: Almost there Posts: 4,443	Re: Mixing Different DDR2 Memory Looks about right there. Glad I could be of help for a change.

02-02-2007	#13
Cavalyr MyCE Senior Member Join Date: Jul 2003 Posts: 392	Re: Mixing Different DDR2 Memory wow..glad that worked out dandy for ya..most nice. __________________ Antec900 Mid Tower MSI K8N-NForce4 Platinum/SLI AMD Athlon64 X2 4800+ 2.4Ghz Toledo S939 2 X 1GB Crucial 2 X 512MB Crucial MSI NVidia GeForce 8600GT PCIe 512MB LiteOn DH20A4P 1 X WD Raptor 36GB HDD 8MB Various Other HDDs for storage

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