Latitude E6400 Owner's Lounge, Part 2

Only Dell can explain why some of the E series use DDR2 and others use DDR3.

However, my guess is that they considered the E6400 and E6500 to be more price-sensitive and, when those notebooks were launched, DDR2 RAM was less expensive.

As already noted, the different RAM options have no impact on performance and, while DDR3 is lower voltage, which potentially saves power, that is offset by the RAM running at a higher frequency.

John

 

maybe you can explain this john, but if it is running at a higher frequency at the same voltage, why isn't that preferable? shouldn't that improve speed without resulting in further battery drain?

 

Watts are proportional to voltage squared x frequency.

So, if DDR2 is 1.8V and DDR3 1.5V (from memory without checking) then, at the same frequency, DDR3 would take 70% of the power of DDR2. However, 1066MHz consumes 33% more power than 800MHz, so the net result is that DDR3-1066 takes 93% of the power of DDR2-800.

Intel's SLFM mode on the mobile CPUs halves the frequency in order to save power. GPUs also reduce their clock speed when running on battery.

John

 

Also, the increased latency in DDR3 may offset some of the advantages it has running at a higher frequency and can even make performance worse if frequency is not increased enough.

 

fully aware of this. that isn't my point. my point is that the reduction in voltage means that it can go faster for roughly the same power drain. and this is GOOD.

this is only an issue until they decrease the latency on ram, which always happens over time. and the frequency gains are enough to offset it, anyway.

 

Hey LPTP-LVR,

If you are replacing an M4400 with an E6400 then I'd be much interested in a comparison between the two when it comes to heat management and fan behaviour and so. For example, when I drive two external monitors with my E6400 while docked the fan is really obnoxious at times. Very loud. Also, when my norton virusscan starts on my E6400 (which stresses my CPU for a while but not more then 20-30%) the fan kicks in at full speed (so much so my office neighbours even notice).

I was in fact thinking of replacing my E6400 with the M4400 specifically for this fan problem (I had the guys from Dell over already a couple of times and after replacing mobo, fan, heatsink twice they all seem to agree that it's normal behavior). I used to have heat issues as well but now I undervolt my CPU this seems to be a bit better. I was thinking to postpone the purchase of M4400 as it is rumoured on this forum they may be getting i7 in Q1 2010.
Thanks

 

Not exactly replacing my M4400...don't think the E6400 would be up for the task I just want to have a lighter laptop with more battery time to bring along to clients and such.
And yeah i think i'd wait for the new platform to get a new performance laptop too. For me it'll probably be end of next year when there will also be faster i7 CPU's (2,8ghz or something)

 

bit late, it expires tomorrow (presumably at midnight), but ....

35% off Latitude E5400/E5500/E6400/E6500 Laptops $899+ Coupon Code: ?LDKKFLGQL9HVP

and i can confirm it works, just picked up an e6400 for my brother.

 

Ordered up an E6400 for my wife. 901 less that coupon plus tax was 803.92. Not bad. Was looking in the outlet and could never find anything I liked. This worked out quite well.

 

glad to help