PC constantly "stalling" after installing new memory module

[Razor1973]

I have 4 DDR slots. Two are occupied by modules with the following configuration, according to PC Wizard 2006:

Manufacturer : Nanya Technology
Part Number : NT512D64S88B0GY-5T
Serial Number : 6243148F
Type : DDR-SDRAM PC3200 (200 MHz) - [DDR-400]
Size : 512 MB (1 rows, 4 banks)
Module Buffered : No
Module Registered : No
Width : 64-bit
Error Correction Capability : No
Max. Burst Length : 8
Refresh : Reduced (.5x)7.8 µs, Self Refresh
Voltage : SSTL 2.5v
Manufacture : Week 80 of 2005
Supported Frequencies : 166 MHz, 200 MHz
CAS Latency (tCL) : 2.5 clocks @166 MHz, 3 clocks @200 MHz
RAS to CAS (tRCD) : 3 clocks @166 MHz, 3 clocks @200 MHz
RAS Precharge (tRP) : 3 clocks @166 MHz, 3 clocks @200 MHz
Cycle Time (tRAS) : 7 clocks @166 MHz, 8 clocks @200 MHz

I just bought a pqi 1GB module from NewEgg.com and installed it. The PC recognizes it, but "stalls" constantly. These are the characteristics of this module:

Manufacturer : MOSEL
Part Number : Unspecified
Serial Number : Unspecified
Type : DDR-SDRAM PC3200 (200 MHz) - [DDR-400]
Size : 1024 MB (2 rows, 4 banks)
Module Buffered : No
Module Registered : No
Width : 64-bit
Error Correction Capability : No
Max. Burst Length : 8
Refresh : Reduced (.5x)7.8 µs, Self Refresh
Voltage : SSTL 2.5v
Manufacture : Week 255 of 2155
Supported Frequencies : 200 MHz
CAS Latency (tCL) : 2.5 clocks @200 MHz
RAS to CAS (tRCD) : 4 clocks @200 MHz
RAS Precharge (tRP) : 4 clocks @200 MHz
Cycle Time (tRAS) : 8 clocks @200 MHz

I noticed tCL, tRCD, tRP and tRAS are different. Could this be causing my stalls? Thing is I bought this off NewEgg and the site specs are not as detailed as I'd need them in order to compare.

TIA! :thumbsup:

 

[Lord Evermore]

What do you mean by "stall"? Actually freeze up and have to be rebooted? Or just freeze up momentarily and then start working again? Does your mainboard support dual-channel, and does it indicate that dual-channel is in effect at the POST screen when all the modules are installed?

Those are just the SPD (serial presence detect) chip programming on the memory modules. They're just programmed that way to tell the system memory controller what settings they're capable of running at. PC Wizard isn't telling you what settings they're actually running at; the system chipset will have automatically set the modules to run at whatever best settings are supported in common between the two. They can't actually be run at different settings. It's possible (though I doubt you've done it as you don't seem knowledgeable about the settings) to manually set the latencies in the BIOS setup to run at something other than what the SPD is programmed for.

Download CPU-Z and it can tell you what latencies your modules are actually running at.

The new memory module appears to be programmed to require higher latencies at 200MHz than your existing modules. That means your Nanya modules will be running at the higher latencies to match the Mosel modules. Although this means slightly lower performance (at most a couple of percent), it should not result in any instabilities in and of itself. Running at higher latencies will tend to make memory MORE stable.

It's possible that the system is for some reason attempting to run at the lower latency settings of the Nanya modules, and that the Mosel modules are not stable at those settings. CPU-Z will be able to confirm that. It's also possible that the Mosel module is simply incompatible with your mainboard. The easiest way to test would be to remove the Nanya modules and run with only the Mosel stick installed, or with one Nanya and the Mosel.

 

[Razor1973]

Lord Evermore, thank you for your reply. I am really having a hard time figuring this one out since, as you said, I do not have the knowledge or expertise, so I appreciate your taking the time to help out.

I meant stall as in temporarily freezing up for about 1 minute. Things get extremelly slow and then they start working normally again.

OK, I downloaded, installed and ran CPU-Z. These are the screens I get. Keep in mind my Slot # 1 is the new 1GB module, Slot # 2 is empty and Slots # 3 & 4 are the original Nanya 512MB modules.

http://pictures.ineverlearn.com/CPUZ_Mainboard.jpg

http://pictures.ineverlearn.com/CPUZ_Memory.jpg

http://pictures.ineverlearn.com/CPUZ_SPD1.jpg

http://pictures.ineverlearn.com/CPUZ_SPD3.jpg

Can you tell me if you see anything wrong here? I could also try your suggestion and run with just the MOSEL module for a while to see if the stalls are still there.

Once again, thank you so much for your help! :thumbsup:

 

[Lord Evermore]

Well it's actually running at only 156MHz (because of the horrible divider situation with Athlon64's), that's not even PC2700 speeds.

Since the Mosel modules don't have any SPD programming for less than 200MHz, the memory controller doesn't have any specifications for what timings to use at that slow a speed. It seems to be choosing a mostly conservative setting, using the timings for 200MHz except for the RAS latency. All that really means is that you could go into the BIOS setup and manually set the timings to be a lot better, but until you know more about what you're doing it's up to you whether you want to play with them.

I doubt however that the timings, since they are already running at such a relaxed setting and the memory is at a low speed, are in fact causing the freezing up issue. It is more likely a compatibility issue. You can try it with the modules in different slots to see what happens. I'd also see what CPU-Z shows for the timings and speed if you're only using the Nanya or Mosel modules alone.

 

[ScrapSilicon]

Originally posted by: Razor1973
Lord Evermore, thank you for your reply. I am really having a hard time figuring this one out since, as you said, I do not have the knowledge or expertise, so I appreciate your taking the time to help out.

I meant stall as in temporarily freezing up for about 1 minute. Things get extremelly slow and then they start working normally again.

OK, I downloaded, installed and ran CPU-Z. These are the screens I get. Keep in mind my Slot # 1 is the new 1GB module, Slot # 2 is empty and Slots # 3 & 4 are the original Nanya 512MB modules.

http://pictures.ineverlearn.com/CPUZ_Mainboard.jpg

http://pictures.ineverlearn.com/CPUZ_Memory.jpg

http://pictures.ineverlearn.com/CPUZ_SPD1.jpg

http://pictures.ineverlearn.com/CPUZ_SPD3.jpg

Can you tell me if you see anything wrong here? I could also try your suggestion and run with just the MOSEL module for a while to see if the stalls are still there.

Once again, thank you so much for your help! :thumbsup:

according to your cpuz mobo screencap ..you have an asus oem A8AE-LE ..according to hp you do not skip any slots :roll: ..I'd put the nanya in the 2 blue slots and the pqi in the closest (towards the cpu) black slot ..also more folks with this mobo have better results with Corsair VS tho..ymmv <edit> had my colors backwards..🙁

 

[Razor1973]

ScrapSilicon, when I got the module, the two Nanya were in the blue slots, as they came from HP and I simply added the MOSEL/pqi in the third. When I first noticed the stall, I switched them the way they are now (MOSEL in 1/blue and Nanyas in 3&4/black) to no avail. 🙁

 

[Razor1973]

Originally posted by: Lord Evermore
Well it's actually running at only 156MHz... that's not even PC2700 speeds.

Scary! Is it even worth the "upgrade"? :|

Originally posted by: Lord Evermore
...because of the horrible divider situation with Athlon64's...

Care to explain or point me to a site that explains this problem?

Originally posted by: Lord Evermore
All that really means is that you could go into the BIOS setup and manually set the timings to be a lot better, but until you know more about what you're doing it's up to you whether you want to play with them.

Would you be able to advise on what settings to use? I just don't know how to make a shot of my bios screen. Or where to find the BIOS documentation/guide online. All the HP site says is "4Mb LPC EEPROM / HP BIOS with enhanced ACPI, DMI, Green, and PnP Features Plus".

Originally posted by: Lord Evermore
It is more likely a compatibility issue. You can try it with the modules in different slots to see what happens.

Please see my previous post regarding this. I still have to try the MOSEL/pqi module by itself, as you suggested. I will do that when I get home from work today.

Originally posted by: Lord Evermore
I'd also see what CPU-Z shows for the timings and speed if you're only using the Nanya or Mosel modules alone.

I will provide those tonight as well.

Once again, thanks a lot! :thumbsup:

 

[Razor1973]

OK, so here is what CPU-Z says when I only have my two 512MB Nanya modules in the primary/blue slots:

http://pictures.ineverlearn.com/CPUZ_MemoryNanyaOnly.jpg

... and when I have the 1GB MOSEL/pqi module by itself in the first of these two slots:

http://pictures.ineverlearn.com/CPUZ_MemoryMoselOnly.jpg

That's how I left the PC for now and will see if I get the stalls. If I don't, should I assume it's a compatibility issue between the two types of memory, return the pqi and get something else?

Thank you! :thumbsup:

 

[Lord Evermore]

Since it's an OEM machine, didn't know that before, just forget anything about manually setting any timings. OEM systems don't generally provide those sorts of options. (Though I could be wrong, they may just be using a standard Asus BIOS but more likely it's customized to hide such options.)

Hmm. Notice that when you use either set by themselves, the frequency is at 199MHz. With the two Nanya modules, you also are running in dual-channel mode. Although the HP service guide says to add memory in the nearest slot to the currently used modules, this appears to be simple generic instruction that does not take into account the dual-channel modes.

It appears that each channel on the board is composed of one blue and one black slot. You should be able to install the modules so that each channel has 1GB total, by placing one Nanya module in the first blue slot, and one in the first black slot, and the PQI module in the second blue slot.

According to the specs for the mainboard, it also supports "400/300MHz DDR memory modules". This would seem to indicate to me that the issue is that when you install a certain amount of memory, the system is automatically going to fall back to the 300MHz DDR speed (which explains why when you have all the modules installed, it shows as 156MHz; frequencies often don't show up as the exact same as what they're set to be by the BIOS). The specs don't indicate exactly what limitations there are with your particular board. Depending on the exact revision of the CPU that you have, this may also be an issue with the memory controller of the CPU, as older revisions did have to reduce memory speeds under certain situations.

Installing 2x512 modules instead of the single 1GB module will at the very least allow you to continue using dual-channel, even if it still causes the memory to run at DDR300 speed. If you have no choice but to use the 300MHz speed, you may as well at least ensure that you don't get stuck doing it with single-channel mode as well.

As for the memory divider thing:

The Athlon64 memory controller does not allow you to simply set a speed for the memory and leave it at that. The memory speed is determined using a divider of the CPU frequency. So installing "PC3200" memory with an Athlon64 doesn't always mean it's running at 400MHz. As you see with just the Nanya modules installed, the FSB😀RAM is CPU speed divided by 11, which makes the memory actually run at (about) 200MHz/400MHz DDR. If you overclocked the CPU, it would also overclock the memory because it would remain at that divider.

For whatever reason, when you install the extra memory module, it's causing the CPU to fall back to a higher divider, which results in the memory running at 1/14th of the CPU clock speed. There are a limited number of dividers that it can choose from, so it has to select whichever one gets your memory to the closest speed to a "standard" setting. I don't think there's an option for a /13 divider, and /12 would be too high, so it falls down to /14. It's not a simple thing to get the memory running at a reasonable speed even with an enthusiast mainboard, doing it with an OEM system is pretty much impossible with a simplified BIOS.

 

[Razor1973]

Lord Evermore, a million thanks once again! You really take the time to help people out and that's quite a virtue.

Yes, it's am OEM machine. I didn't mention it before because I just learned from you about the BIOS "crippling", which indeed they did. I went to the BIOS setup and these settings were nowhere to be found. I will be building my next PC, as I have the previous ones. This was just too good of a deal to pass up.

So other than the fact that I will not have any slots left to upgrade memory any further, would you recommend that I return the 1GB module and get two 512MB ones as that will give me better performance?