Solved Memory Upgrade slow system

R

rmomota

Hi!
I've got an old HP EliteBook 840G1 laptop

I just decided to give my system twice the memory, it's now 16GB (2x 8GB), before it got 8GB (2x 4GB).
The first boot the system was extremely slow but then I got that the extremely slow issue happens sometimes.
In the BIOS it detects the memory just fine and the system seems to be detecting the memory just fine as well.
When it boots fine all the system works great, but when it boot slow all the system is also very slow.
The first symptom of a super slow system is just right at the
Feeding entropy
Loading kernel modules
boot messages, becomes very slow since there.
I already did a memory test with BIOS tools and it did alright, no problems detected.
So I decided to switch memory in sockets and still the same the problem persist, I mean sometimes it's super slow sometimes not.
So I did another test and test each chip alone and did the test with both memory chips and the problem never happens.
When both sockets have the 2x 4GB it never happens too so it's not a socket problem.
Seems to happen only with both 2x8GB installed.

So every time the boot is super slow I just reboot and try again until it's a good boot and it's kind of annoying to keep doing this.

This laptop supports 16GB limit so I really don't know what's causing this but it's clearly memory related issues.

I noticed when it's slow the 4 CPU/cores are 100%

Any clues?
 
rmomota said:
This laptop supports 16GB limit so I really don't know what's causing this.
Click to expand...
If memory was an issue you'd have weird crashes and/or panics, not general slowness.

I would take a look at the state of this disk. Use smartctl(8) to look at the SMART data of the disk.
 
Do you still have the old memory? I would cross-check that it is still slow with the old memory.

I never heard of a slowdown like that. Except for the memory tuning on AM5 socket systems.
 
Make sure both SODIMMs are the same speed and have the same wait states.
 
Both are same brand, same specs, a pair from the same box.
# dmidecode 3.5
Scanning /dev/mem for entry point.
SMBIOS 2.7 present.

Handle 0x0005, DMI type 16, 23 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 2

Handle 0x0006, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 1(left)
Bank Locator: BANK 0
Type: DDR3
Type Detail: Synchronous
Speed: 1600 MT/s
Manufacturer: Hynix/Hyundai
Serial Number: 00664197
Asset Tag: 9876543210
Part Number: HMT41GS6AFR8A-PB
Rank: Unknown
Configured Memory Speed: Unknown

Handle 0x0008, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x0005
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: SODIMM
Set: None
Locator: Bottom-Slot 2(right)
Bank Locator: BANK 2
Type: DDR3
Type Detail: Synchronous
Speed: 1600 MT/s
Manufacturer: Hynix/Hyundai
Serial Number: 00664197
Asset Tag: 9876543210
Part Number: HMT41GS6AFR8A-PB
Rank: Unknown
Configured Memory Speed: Unknown
 
cracauer@ said:
Do you still have the old memory? I would cross-check that it is still slow with the old memory.

I never heard of a slowdown like that. Except for the memory tuning on AM5 socket systems.
Click to expand...
I did try that.
Never gets slow with old and never gets slow when using a single new 8GB.
It only gets slow with the pair together but sometimes it runs just great just like now.
When I mean slow I mean it takes about 10 minutes to boot into xfce and it's impossible to work, takes forever to open something, it's really slow and CPU 100%.

I just remember that I updated from 13.2 p2 to 13.2 p4 few days ago, before the new RAM arrived, but never noticed this problem until now.
Can it be the a kernel loading issue?
What could cause a persistent 100% CPU at boot on kernel load?
And the issue goes away with 8GB memory only?
 
I don't know the entropy algorithm or the sources that FreeBSD uses. I don't really know the small parts of any OS.
So I'm wondering if the entropy bits may be decreasing due to more memory space, or simply the L1/L2 cache may be posing a bottleneck on the CPU cycles/RAM ratio.
I'm probably out of touch with reality.
 
rmomota said:
I did try that.
Never gets slow with old and never gets slow when using a single new 8GB.
It only gets slow with the pair together but sometimes it runs just great just like now.
When I mean slow I mean it takes about 10 minutes to boot into xfce and it's impossible to work, takes forever to open something, it's really slow and CPU 100%.

I just remember that I updated from 13.2 p2 to 13.2 p4 few days ago, before the new RAM arrived, but never noticed this problem until now.
Can it be the a kernel loading issue?
What could cause a persistent 100% CPU at boot on kernel load?
And the issue goes away with 8GB memory only?
Click to expand...

Surely this is a BIOS issue, no?

Can you get a single 16 GB DIMM instead?
 
OP,
For starters ensure the integrity of your RAM.
I've used MEMTEST for years on my client's hardware.
Dual or Triple channel RAM (XEON) has higher throughput than single channel.

Decades ago while at IBM, we used dual channel cables on high speed disk storage.
This doubled throughput by allowing one interface to ring out after transmission, while continuing transmission on the other path.
This method cuts the latency in half, or one-third.

The link below will let you create a bootable USB or CD media.

www.memtest.org

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)
www.memtest.org www.memtest.org
 
CuatroTorres said:
Is the 4GB memory DDR3L and the new DDR3? Could this affect performance beyond battery or compatibility?

HP EliteBook 840 G1 Notebook PC Product Specifications | HP® Customer Support

HP EliteBook 840 G1 Notebook PC Product Specifications
support.hp.com support.hp.com

cracauer@, a single DIMM loses dual-channel functionality.

UPDATE:

Compare dimms with decode-dimms() (sysutils/i2c-tools).
Click to expand...
But when with 2x4GB this never happens.
What makes me so confused is that it happens like 50% of times, if it's a compatibility issue the problem would be always there, right?
I think I will have to learn to live with this.
 
CuatroTorres said:
Is the 4GB memory DDR3L and the new DDR3? Could this affect performance beyond battery or compatibility?

HP EliteBook 840 G1 Notebook PC Product Specifications | HP® Customer Support

HP EliteBook 840 G1 Notebook PC Product Specifications
support.hp.com support.hp.com

cracauer@, a single DIMM loses dual-channel functionality.

UPDATE:

Compare dimms with decode-dimms() (sysutils/i2c-tools).
Click to expand...
The SODIMM I got is also DDR3L, 1.35v, well in label it is so I believe it.
Well, in fact in the specs it shows DDR3/DDR3L 1.35v-1.50v, should work for both.
 
Well, I will try to look what causes the 100% CPU, seems the reason of it all.
Another test I can do is boot with some linux live image from USB and check if it happens.
So there's still some troubleshooting options left.

Thank you!
 
When I mean slow I mean it takes about 10 minutes to boot into xfce and it's impossible to work, takes forever to open something, it's really slow and CPU 100%.
...
I think I will have to learn to live with this.
Click to expand...
It doesn't seem like something one should live with.
 
rmomota said:
[...] So I did another test and test each chip alone and did the test with both memory chips and the problem never happens.
Click to expand...
I assume your laptop has exactly two memory slots. Have you tried each new 8 GB module alone in "the first" slot and in "the other" slot? (That's four different situations in total.) I don't know when only one module is inserted it has to be in a specific slot though ...
 
Erichans said:
I assume your laptop has exactly two memory slots. Have you tried each new 8 GB module alone in "the first" slot and in "the other" slot? (That's four different situations in total.) I don't know when only one module is inserted it has to be in a specific slot though ...
Click to expand...
I'm not sure if the 2nd slot can be used with an empty 1st slot.
That's the only situation I did not try yet.
Tested both individually but always in the 1st slot and both work just fine always.
 
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