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Inspiron 5150 Matrix Lag Quick Fix


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Okay, since not many people know exactly what this will do, So I posted this in it's own little topic here.

What is matrix lag?

Well matrix lag is a problem most Inspiron 5150 owners have a problem with. It's where the game goes into a kind of slow motion, where the framerates are still silky smooth, and there's no extra harddrive activity going on. I had a problem with this for a year and a half, starts happening after the first format of a brand new I5150.

I dont have a problem with heat.

Good for you, then you probably wont have the matrix lag problem either. This tweak is still really nice because it doubles your battery life, without sacrificing ANY performance! Or, if you just dislike that really noisy fan (maybe because it's embarassing during a quiet class, meeting, or just annoying) it will make the laptop run so cool that the fan almost never turns on.

But how much battery life can I expect?

Okay, I used to take my laptop to school with me, and during spares classes I'd sit in the lounge and play a few games. With the processor running at full speed, I'd get about 45 minutes of gaming time, and up to 1.5 hours of text/whatever else. After this tweak I get a full 2 hours of gaming time, and upward of 3+ hours of text editing.

Cool, so how do I do it?

Just follow these simple steps:

Step 1:

Go to http://www.diefer.de/speedswitchxp/ and download Speedswitch XP (<--direct download). Then install it wherever, and reboot if it asks you to.

Step 2:

Speedswitch XP will show up as a little green/blue flag down by the clock on your system tray. Right click it, and click on "Battery Optimized" (this will change the flag to a blue flag with a green square in the middle if you did it right, give it up to 5 seconds, though it usually only takes 0.5s)

Step 3:

Reboot your computer, press F2 during the Dell BIOS screen to enter the bios, enter any passwords you may have set. Press ALT+O (thats hold alt and press the O button lol) until you come to a BIOS screen listing Hyperthreading and Speedstep options. (If I remember right, its the next screen, or the screen after the big battery screen). From there, select Speedstep: Enabled (only enabled will highlight) and press > (right arrow button) Until it says Disabled. Then press ESC and save and reboot.


Wow, is that all there is to it?

You're done! double battery life, no matrix lag, and same performance. Performance only declines for stuff like installation programs, if it's running too slow for you at any given moment, simply right click the flag again, and click Max performance. Yes, I am the first and probably only one who has posted this on the internet. I found the solution to my problem, maybe you dont have the same prob, but it's still a cool tweak.

Edited by mew905
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i did what you said above and it seemed good, but when I play WoW, my fan was completely silent throughout my playing time...so about 10 minutes in i just quit because I didn't know how that would affect my laptop. Is tihis supposed to happen? Thanks in advance

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I believe one of the statements you make should be clarified. You stated: "This tweak is still really nice because it doubles your battery life, without sacrificing ANY performance!"

I *believe*, and I may be wrong (please correct me if I am) that you are stating that with this one game you are not seeing any performance degredation with the tweaks you outline, correct? If so, then it should be made clear that other games and applications (not just installer type programs you mention) may see a performance decrease. It looks to me that you may not be seeing a performance decrease for this one game because it is more graphics card bound than CPU bound in its needs for horse power on your system. That you are seeing a lack of lag makes sense sense you are not generating near the amount of heat. Other programs that may demand more processor power will see a decrease in performance, if my understanding is correct.

I state the above because after reading the information the author of SpeedSwitchXP has on his site, it seems that the setting you suggest "Battery Optomized" is actually throttling down the CPU and locking it at that lower speed. The author states that it "keeps the CPU at the lower speed (i.e. a Mobile Pentium 3-M@1GHz runs at 733MHz continously)" The key word in that line is *keeps*. This as opposed to the "Dynamic" setting where the author states "switches between the lower and maximum speed according to current CPU utilization (i.e. a Mobile Pentium 3-M@1GHz switches automatically between 733MHz and 1GHz)".

SpeedSwitch seems to offer more fine grained and dynamic controll of SpeedStep settings (dynamic control is lacking in XP)...which makes this a very cool (no pun intended) little app. I just wanted to make it clear to other board members that from my understanding, that CPU performance bound apps (or those with lower speed CPUs) can see a performance decrease with the settings you suggest.

Anyway, thanks for posting info on the SpeedSwich app...very cool...I am about to install soon as I post this.

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Can I get a bit of clarification. I was under the impression that SpeedStep was what switched CPU speeds based on utilization, am I wrong? Does the SpeedSwitch XP do something that SpeedStep cannot? I'm not sure what the difference between the two are, are they both necessary do you think for laptop gamers like me?

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Answers to replies:

Reply # 1:

Yes, the fan isn't supposed to come on nearly as often because the CPU is running at such a slower speed (1.6GHz calculated, 908 via windows XP) it doesnt run as hot, therefore the laptop doesnt need to run the fan as much, saves fan life, and one less thing to drain power.

Reply # 2:

Windows based programs *may* see a performance decrease. Direct X and OpenGL games run at the same performance. Here's a list of games I play where the tweak had no effect (or a better one) on performance:

Global Operations

Midtown Madness 2

SimCity 4 Deluxe

Starcraft - Broodwar

Doom 3

Counter Strike (CS Source is untested)

Diablo 2 - Lord of Destruction

World of Warcraft

The Sims 2

C&C Tiberian Sun

Aliens Versus Predator 2 - Primal Hunt

Command and Conquer Generals - Zero Hour


Gunbound World Champion

Need for Speed Most Wanted

Need for Speed Underground 1 & 2

Need for Speed Hot Pursiut 2


With that range of games unaffected in performance, I have no doubts many, many more will experience the same effect.

Windows based media players have had little or no noticable effect while streaming or playing videos. Of course, I have not actually benchmarked these, so I dont know if there actually IS a hit on performance. I will benchmark games with and without the tweaks if there is enough demand.

Reply # 3:

Speedswitch XP (referred to as SSXP) simply controls the Speedstep feature on the CPU, just like the control panel. Fortunately SSXP provides almost total control with the basic features. The control panel is more automatic. Basically, when overheating at max speed (in my case, 2.8GHz) it drops the speed down to 1.6GHz (it's slowest speed via speedstep) to cool off. With the tweak, the CPU will rarely get that warm (if ever), if it does, it simply lags like normal, rather than the annoying matrix lag.

One thing you will notice for some games is that if you set the processor at max speed after turning off Speedstep in the BIOS, your game will run in turbo speed, then when the matrix lag hits it will run normally (this is what got me thinking about how to fix it)

Edited by mew905
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if iw anted my laptop to run continuously at 2.8 without throttling it back to 1.6, etc, then would setting my power options to the "Always On" option work? or do i have to do something else as well? battery life isn't an issue as I always leave my laptop on AC in my dorm room and in fact, I take out the battery from the system completely and store it in a different location.

I deleted the speedswitch xp program because I thought I could do without it, and my windows started hanging on the loading screen O_O, so i re-enabled speedstep in F2 and it worked again, whew. Didn't get what was going on for a sec...

Edited by daonesteven
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Windows will hang during loading without Speedswitch XP set on max battery and Speedstep turned off. If you dont really care about heat, and your laptop is never run on batteries, and you dont have the matrix lag problem, then good for you. This is a tweak to maximise battery, reduce heat and stop matrix lag. My laptop had this problem, and many other people did too. Dell will simply say the video card is outdated.

You're one of the few lucky ones :)

EDIT: Forgot to mention Windows XP's built in speedstep driver sucks. Always on will not force the processor to run at max speed all the time, it is over-ridden in the BIOS when temperatures get too high. Speedswitch XP will not help either if set to max performance and speedstep in BIOS is on (believe me, I've tried just about every method to stop matrix lag, both physically and software, excluding replacing thermal gel on the processor).

Edited by ®®®
Removed Full Quotation of Previous Post
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  • 3 weeks later...

Ya know, I should patent this, take it off the net, and sell it :) I'm in need of cash pretty bad right now. Say $5 sound like a good deal? its about the same price to buy and ship thermal gel lol. Of course I'll build a program to do it with some kind of anti-piracy mechanism... or if people wanna donate to me as a "thank you" I can proceed with other tweaks and mods for the I5150 :) lol.

Course you guys know I'm just kiddin but any help out here would be MUCHO appreciated x.x

EDIT: I feel kinda bad now posting that, practically begging online XD

Edited by mew905
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i dont get it.

if you turn of speedstep, whats the use of going to "max. speed"? it would stay on the low setting anyway.

so for my laptop, "battery optimized" would make it go down to 1.5 ghz.

THAT is my windows-setting. when i play games on 1.5 ghz, i have matrix-lags and low-fps.

when i turn back to 3 ghz and play, i have nice running games without lags.

sorry, i consider this guide as useless. feel free to correct me, if i got something wrong.

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I believe in the case of mew905, he found that he was getting matrix lag due to heat (probably causing throttling of his GPU). His guide is good for those games and apps that are not cpu bound performance wise. If a game is perfectly capable of running smooth on a 1.5Ghz cpu, throttling down your 3GHz cpu to 1.5 will not effect performance....and will reduce heat, keeping your GPU happy and running full tilt.

so for my laptop, "battery optimized" would make it go down to 1.5 ghz.

THAT is my windows-setting. when i play games on 1.5 ghz, i have matrix-lags and low-fps.

when i turn back to 3 ghz and play, i have nice running games without lags.

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Actually for the Inspiron 5150, turning off speedstep alone will cause the laptop to run "turbo speed" for most newer games. It actually doesnt drop the speed with speedstep off. Max performance runs it at 2.8GHz, but it seems to only affect new games. At max battery or battery optimized after turning off speedstep, games run normal speed, framerates stay steady, reduce heat, reduce lag, double battery, etc. Its just a better overall tweak. Of course, you dont have to do it if you dont want, this was a general tweak for I5150's because most of them have heat issues, resulting in matrix lag. I dont have access to any other laptops but I'm sure if the matrix lag problem exists on others, this should still work.

BTW, for the GeForce FX Go5200 overclock benchmark I did (it's stickied), all of my tests were done after applying this tweak. so no, there actually isnt a decline in performance in terms of gaming. I havent done any CPU tests though.

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