34 replies to this topic

[bondisdead]

I am having a weird problem with a gaming PC I am building for somebody. It's based on the Gigabyte Z68XP-UD3 mobo, an Intel Core i5-2500k CPU and Windows 7 64-bit on a Crucial m4 64GB SSD. With only 8GB of RAM installed (either G.Skill Sniper or Corsair Vengeance 2x4GB), the system boots up really fast as expected, applications open quickly, etc. However, whenever I install the remaining 2x4GB sticks from the kit, for a total of 16GB, the system becomes really sluggish. Bootup time is slowed down dramatically, applications take time to open/close. There is a general sluggishness. I run memtest, and it's just fine. As I said, system is stable, but sluggish. I have updated to latest BIOS, and reset to safe parameters (including RAM speed of 1333MHz and default CPU speed).

I suppose the CPU could be bad, but that doesn't seem likely. Why would the extra RAM create this problem??

[jmwills]

Probably a bad stick. I would mark them 1-4 and test independently of one another. Either that or one of the DIMM slots is bad.

[bondisdead]

Probably a bad stick. I would mark them 1-4 and test independently of one another. Either that or one of the DIMM slots is bad.

I initially thought the same thing, but I have two 16GB kits (4x4GB): Corsair Vengeance and G.Skill Sniper. Either kits has the same problem when all four slots are populated. If I only populate two slots, system is fast. With only 2-sticks installed, I tried both slot pairs (1/3 + 2/4), and the system is fine. It only pops up when all four slots are populated. Memtest is fine, it's just that something is severely bottlenecking things.

[dvn]

I've heard it mentioned that some mobos just don't deal well with all 4 slots filled, for whatever reason. I remember pcdoc saying he'd go with 2x8 before 4x4.

Sent from my SAMSUNG-SGH-I777 using Tapatalk 2

[ikon]

That is a pretty weird problem. I've never has the misfortune to experience it myself. I can think of 2 options: verify all the RAM sticks by trying them on another mobo, and/or search the net to find out the peculiarities of that specific mobo.

[no-control]

Check to make sure all the sticks are running on the same JDEC/XMP profile. I would also verify RAM settings. While in BIOS how are the RAM voltages? Any dips? Try moving the voltage up a bit.

[pcdoc]

This is not uncommon and relates to timing. As we have mentioned on the podcast several times some of these modules/motherboards can be temperamental. Sine you have already done most of what I would have suggested the only thing left is to manually set the timings of DDR yourself. Make sure you are using all exactly the same brand and type over the 4 DIMMS go into the BIOS and manually set the memory timings to match what is on the modules. I know you mentioned you tried both Corsair and Gskill but you did not say if all 4 slots where exactly the same.

[bondisdead]

This is not uncommon and relates to timing. As we have mentioned on the podcast several times some of these modules/motherboards can be temperamental. Sine you have already done most of what I would have suggested the only thing left is to manually set the timings of DDR yourself. Make sure you are using all exactly the same brand and type over the 4 DIMMS go into the BIOS and manually set the memory timings to match what is on the modules. I know you mentioned you tried both Corsair and Gskill but you did not say if all 4 slots where exactly the same.

The BYOB guys are active on a Sunday afternoon, and a nice one we have in southern cal today. ;-)

I was only using the same kit sticks in each configuration. I initially used the Corsair Vengeance in all four slots. I reset BIOS to default safe settings, then went in and enabled XMP for 1600MHz. I confirmed that timings were the same for all four stix. In Windows, CPU-Z reports the proper RAM speed (800MHz) and timings (9/9/9/24). The RAM is set to 1.5V. I then repeated this same operation with the G.Skill. The Corsair RAM has not been used/tested before, but the G.Skill was pulled from an ASUS P7P67 PRO that had no issues with 16GB.

I have read that people are successful with 16GB on this particular motherboard, so maybe I have some sort of weird lemon.

[jmwills]

The reason I mentioned a bad DIMM slot is that it happened to me one time and I chased that dog for about a week.

[pcdoc]

The BYOB guys are active on a Sunday afternoon, and a nice one we have in southern cal today. ;-)

I was only using the same kit sticks in each configuration. I initially used the Corsair Vengeance in all four slots. I reset BIOS to default safe settings, then went in and enabled XMP for 1600MHz. I confirmed that timings were the same for all four stix. In Windows, CPU-Z reports the proper RAM speed (800MHz) and timings (9/9/9/24). The RAM is set to 1.5V. I then repeated this same operation with the G.Skill. The Corsair RAM has not been used/tested before, but the G.Skill was pulled from an ASUS P7P67 PRO that had no issues with 16GB.

I have read that people are successful with 16GB on this particular motherboard, so maybe I have some sort of weird lemon.

Possible, I have two of these both with 16 gigs and no issues and no special setup. That does not mean that one of you slots is not bad as this is not uncommon for any motherboard MFG.

[ikon]

The reason I mentioned a bad DIMM slot is that it happened to me one time and I chased that dog for about a week.

Possible, I have two of these both with 16 gigs and no issues and no special setup. That does not mean that one of you slots is not bad as this is not uncommon for any motherboard MFG.

Could a bad slot really lead to poor performance? At first glance it would seem more likely that it would lead to the system not being bootable. Or, at least, the system only posting the amount of RAM for the 3 working slots. I'm just curious, cause I've never encountered this.

[mrossco]

This issue screams voltage. Are you sure that the specific models of RAM you are using are supposed to run at 1.5V and not 1.65V? Also check your system health in the BIOS and make sure all your voltages are in range. If they're all on the low side, it could be a sign of a bad board.

[ikon]

This issue screams voltage. Are you sure that the specific models of RAM you are using are supposed to run at 1.5V and not 1.65V? Also check your system health in the BIOS and make sure all your voltages are in range. If they're all on the low side, it could be a sign of a bad board.

OK, I could see where this might have some effect on performance, like pcdoc was alluding to earlier.

[pcdoc]

Any and all are possible with memory. I would not load the XMP profile yet and see if runs any better. The other thing (which is long shot) is lock down you pagefile and make sure it has been set to a fixed value. With that much ram, your system will allocate too much pagefile and it "could" give the perception of being slower.

[bondisdead]

Both 16GB (4x4GB) sets of RAM are rated at 1600MHz with 9-9-9-24 timings with 1.5V (G.Skill Sniper + Corsair Vengeance). In the BIOS, I reset overything to factory settings, then updated things like AHCI, boot order, etc. The RAM defaults to 1333MHz at 1.5V.

I re-ran memtest with these settings all day yesterday, and they passed without a single error.

Note that the WEI is reported as 7.9 when the memory speed is 1600MHz. However, it takes an excruciatingly long time to run (ie. way more than normal).

Booting into windows is sloooow. At least 2-minutes with a Crucial m4 64GB SSD with a fresh install of Windows 7. It took over 2-hours to install windows on this SSD, which is crazy! Due to this slow install time, I initially thought it was the SSD that was bad. After completing the install, that was when I noticed the slow boot time, and realized that something was wrong. I replaced the new SSD with a known good spindle drive. Same slow boot issue, and overall sluggish performance. The cursor will freeze for about 20-seconds once the desktop is displayed. Anyways, after reading up on forums and experimenting, I discovered that it was the 16GB of RAM being installed that would call the problem.

Oh, and I did already reduce the pagefile to 1GB.

After talking with Gigabyte, they suggesting swapping out the CPU since the the memory controller is built-into the chip. I put in an Intel Core i3-2100, and there was no improvement in performance. I did try another power-supply as well. I think this isolates the motherboard.

Gigabyte wanted my configuration so they could duplicate the setup. As others here have reported using this board with 16GB of RAM, I can't imagine it's an inherent design problem.

Here is my system configuration. It is being bench-tested, outside of a computer case.

• Gigabyte GA-Z68XP-UD3 (HW: rev 1.3 ; BIOS: F9)
• Intel Core i5-2500k CPU / Intel Core i3-2100 CPU
• Corsair Vengeance PC3-12800 16GB (4x4G) Kit (CMZ16GX3M4A1600C9)
• Antec EarthWatt EA-650 Power-Supply
• Crucial m4 64GB SSD
• Microsoft Keyboard/Mouse USB 2.0
• HDMI connection to motherboard (no video card)
• Ethernet connection to home network
• No other ports connected

If I had not need the 16GB, I wouldn’t have had any issues!

This issue screams voltage. Are you sure that the specific models of RAM you are using are supposed to run at 1.5V and not 1.65V? Also check your system health in the BIOS and make sure all your voltages are in range. If they're all on the low side, it could be a sign of a bad board.

Any suggestions of what I should look for in particular?

Edited by bondisdead, 18 April 2012 - 10:04 AM.

[jmwills]

If you reset the board to the default settings, verify the voltage and timing settings once again.

[mrossco]

Any suggestions of what I should look for in particular?

Somewhere in the BIOS, there should be a page that shows you system health information, and it should include information on each of the voltage ranges your motherboard uses. Very rarely will you ever see, for example, that the 5V circuits on your motherboard will read exactly 5V. Instead it will fall into some range around 5V. Your motherboard will have an acceptable range for this, and you need to make sure that you are getting the appropriate voltage for that range. Most motherboards will give you a warning if something is either too high or too low.

I'm grasping at straws here, as with all the motherboards I've worked with (a lot), I've only ever had one where this was the problem.

Other things to look at?...

- Try bumpiung up the memory one tick above 1.5V
- If you can, get your hands on another z68 mobo with 4 slots. Memtest is good, but it doesn't always catch everything.
- I know you've tested your memory already, but do re-run Memtest on each of the 4 memory modules individually. Use a can of air to blow out the slots between runs.

Load set up defaults, enable XMP, and disable USB legacy support. I've heard that USB legacy support can cause false positives in memtest, but I've never personally seen it. Make sure you're using the latest version of memtest. Let it run about 4 passes each or until you get an error.

I don't envy you, as I'm sure many of us have racked our heads against the wall on similar types of issues. Your hardware is good, and everything should be working. It just isn't.

[bondisdead]

I was looking at the voltages in BIOS earlier, but was more curious what were considered acceptable/unacceptable levels.

I will try and bump the memory voltage to 1.6V, to see if that makes any difference.

Meanwhile, I will try the RAM in another Z68 that I have, which is a gigabyte Z68MA-D2H.

It's just strange that the memory seems to be working properly, but is causing the system to operate slowly! I did run Prime95 with memory max'd out, and it ran w/out any issues.

[ikon]

definitely a case of the end being more than the sum of the parts. Have you, by any chance, mixed the brands of memory (2 of each brand), just as a test, to see if it makes any difference? I know that wouldn't normally be recommended but, at this point, it would it's time to try crazy stuff.

[bondisdead]

definitely a case of the end being more than the sum of the parts. Have you, by any chance, mixed the brands of memory (2 of each brand), just as a test, to see if it makes any difference? I know that wouldn't normally be recommended but, at this point, it would it's time to try crazy stuff.

I'll try it when I get home! I agree, try everything out there. ;-) The easy thing to do would be to RMA the board back to Gigabyte, but as I have another board to use for the gaming pc I am building, I consider this a challenge to figure it out. As I have found in the past, sometimes the problem ends up being an area that appears to have no relation to the problem. I was sure I had a bad SSD originally, and it was just a fluke that I tried testing with less RAM.