skottmorris
1 Copper

Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

I recently updated my Dell m4800 to BIOS A8 with Windows 7 64. I had been using a collection of older power adapters from my previous Dell m4400 without any issues. After the update, wow. A huge performance hit if I do not have the 19.5 volt and 9.23 amp adapter connected.

The m4400 power adapter is 19.5 volt and 6.7 amp. Pretty close right? Not any more.

I do have it connected to a Dell docking station almost all the time. Just checked. They are both 6.7 amp.

Anyone know what changed in BIOS A8 and what the deal is with the performance? Looks like I need to request a new docking station, but I'm not sure IT will believe my story.

7 Replies
andre372
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

I'd like an explanation from Dell as well.

If I'm correct, the crippling started with A07. I have the i7-4900MQ CPU with "Max Qualified Speed" at 2.80 GHz (multiplier 28) and "Max Turbo Boost" speed at 3.79 GHz (x38 ratio). Independent of the BIOS version (A06, 07, 08 or 09), when on the 180W AC power adapter, the CPU runs at x36 ratio i.e 3.59GHz. Even without any processing load. The same goes for battery power, whatever the BIOS version, the CPU speed is at x 34 ratio i.e 3.39 GHz. Again, without any load. On battery power the CPU is at a higher speed than the "Max Qualified Speed" without any need for the Turbo Boost.

Now the problem arose with the version A07 and exists in all of the following versions. When you plug in an adapter which is less than 180W, I have several of the 130W ones, the CPU multiplier drops to 8 which is the absolute minimum and makes up 800MHz. Ridiculous! Right after you remove the power supply you get an immense 3.39 GHz, over 4 times the speed when on AC.

As I need to use the laptop on a dock which has the 130W power supply weekly, I've reverted to BIOS A06 first. The computer is unusable at 800 MHz, it's like going 15 years back in time. The most noticable feature of the newer BIOSes that I like is that they somehow optimize the fans and make them quieter.

Does anyone if there is a limit on how many times the BIOS chip can be flashed?

I'd like Dell to explain why they have made such a move. And eventually fix this with A10!

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RyanHilliker
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

I can confirm this from my organization as well. On our E6440's if users use the following:

  • Universal Power Supplies (that meet the power requirements)
  • Dell 60W Power Supplies

It'll basically cripple the laptop causing device problems, sound problems, video problems, performance problems.

Unplugging the power supply resolves the issue immediately in all cases.

gazofnaz
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

Anyone know what changed in BIOS A8 and what the deal is with the performance?

I would like to know this too.

I have a workaround for the problem, but it is a workaround and not a fix.

Go into the BIOS (F2 during boot), go to the performance tab, and disable "Intel Speed Step" technology.

I won't go into detail about what speed step does, google will do a better job at that. The effects you should notice are:

1) Increased performance, on docked, plugged, and battery

2) decreased battery life due to increased performance.

wjogert
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

"why" seems to be fairly simple to answer... force Dell users to purchase expensive OEM chargers by crippling their performance if a cheaper aftermarket charger is used.

The center pin on the charger carries a data stream.  It reports information to the BIOS, including power supply ID information.  Aftermarket chargers without a center pin, or without the proper data stream, or under-rated Dell supplies, will cause the laptop to reduce CPU speed to minimum and often refuse to charge the battery (check the icon, it might say "On AC, not charging")

Dell will claim that the speed reduction is to allow the laptop to continue working without the ability to charge due to under-rated power supply... which is ***.  A 130W or 150W charger would work just fine if you're not gaming at full CPU and GPU usage.

AJameson56
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

This thread helped me figure out this problem.  The workaround provided by gazofnaz seems to have worked for me.

There was one difference that I wanted to document for anyone who comes searching.  I have bios version A14.  I have also been having slow performance when I am unplugged, as well as when I am on a <180W adapter.  I wonder if they decided to "help their users save battery life" by this idiotic performance cut when not plugged in at all.

Has anyone else experienced that?  Previously it seems you could unplug your 120W adapter (for example) and performance would go back up.  I almost always work plugged in, so I'm not sure when my issue started occurring.  

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Pinguli
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

I worked with an M4600 at a customer and were up to equip my company with these machines.

But then I had to carry the extremely heavy original power supply (230W or so) - absolutely not suited for a mobile computer!

As I connected a smaller power supply from Dell, I also experienced this problem of extreme

loss of performance.

I measured the power consumption: it is at about 32 W - the small Dell power supply (well suited for traveling) delivers up to 130 W! Obviously there is no technical reason for this strong throtteling.

This customer treatment is preventing me from equipping my company with Dell.

JanZanden
1 Copper

RE: Slow Performance without proper Power Adapter after BIOS A8 update on M4800?

There is an excellent solution to this problem: use ThrottleStop.exe and set multiplier to 20 and Power Save. Everything runs as you would like savely.....