Anyone Tried ZVVN Memory? Don't!

[The Doktor]

OK, I'm not usually one to post about a defective computer product, it's something that happens once in a while. But this is a special case.

 My most commonly used computer is one that I built back in 2007, it is obviously old, but fairly well specc'ed. It has been running a Core 2 quad (Q9450) and 8 GB of memory since I built it, and is still a very Snappy and stable system. I typically have many programs open at once, along with often 20 or so tabs in the web browser. Never really a problem, but more memory would be nice. I would have installed more when I built it, but back then DDR2 sticks bigger than 2GB cost a fortune.

 So, I'm searching eBay to see if I can find any larger sticks of used DDR2. Well, no major name brands, but I found somebody selling a used kit of 4 4GB sticks. Not a brand I've ever heard of, it was called ZVVN. Apparently something the Chinese are putting out. I ordered the set from him, put in one stick just to make sure it was definitely compatible with the computer , worked okay. Added the other three, couldn't even get to the BIOS screen. Would just turn on and then restart over and over again, never even powered up the display. Figured it was defective, got a refund.

 There are several sellers selling this same memory brand new. So I order another 16GB kit, new this time. Should be good. Well, got the memory today. Installed it and hit the power switch, seems to be working okay, Windows was starting to load. Up comes a blue screen. Haven't seen one of those for years , had a pretty good idea where it came from.

 Restart into memtest86+ this time. I'm a little surprised, it goes through the first four tests with no errors. Then comes test number five. Get into that 1 a little bit, spits out 16 errors. I'm figuring okay, when defective stick, it happens. I'll figure out which one and get it sorted. Test continues, another 8 errors pop up, address suggests this is probably a different stick. Before it's finished test number 5, another 40 errors pop up, the address suggests this is yet another stick. So out a four sticks, I've definitely got at least two, possibly three bad. This is not bad luck, this is junk, it needs to go back in the dumpster it came from.

 Another little detail or two I should mention. In memtest, it was listing memory as G-Skill with a timing of 6-6-6-18(as advertised , but wrong brand). Also, the memory was rather warm when I removed it, not enough to burn you, but a whole lot hotter than the Mushkin I had in there before. Or any memory I've ever touched, for that matter. I don't know if this stuff is built from Rejects, or if they are taking some other form of memory chip and trying to run it as ddr2-800 , but if you ever find yourself thinking about trying it, take my advice and do not. You will not be happy with the results.

[golden_labels]

Congratulations on becoming among the top search results for “ZVVN”!

If you can control that for your hardware: what happens, if you run it at 6-6-6-15 timings?

[Nominal Animal]

Yup, looks like defective to me too.   Personally, I like to run memtest86 over a weekend with zero errors before I trust a new machine – either self-built or store-bought.

As an aside, you might also want to check your motherboard manual and memory QVL, as to which configurations of four memory sticks it does support.

If you look at say ASRock X670E Pro RS for AMD5 socket, you'll see that there are only two verified to work when all four sockets are populated: 16 GB Corsair CMT64GX5M4B5600C36 ver 4.43.02 DDR5 at 5600 MHz with Samsung chips, or KLEVV KD5AGUA80-56G4600 DDR5 at 5600 MHz with SK Hynix chips, both for 32 GB (2x) or 64 GB (4x) total RAM.
They both are rank 1Rx8, so for this motherboard, I'd verify the memory I'd get is also rank 1Rx8.

(Rank describes how the memory is organized in the stick.  Often, but not always by any means, single-sided are 1Rx8, and double-sided are 2Rx8, but you absolutely cannot rely on that!)

Then again, I'm very cautious myself with non-ECC RAM, because I absolutely hate it when my computer silently garbles my data or crashes for no reason.
(I used to be a HPC cluster sysadmin for a few years, among many other things, and some of that stuff has rubbed on me indelibly: I'm odd nowadays.)

You might wish to run memtest86 with only one stick installed (check which slot is the single-slot one from your motherboard manual), as well as only one pair installed (again, check the slots from the manual), to identify whether they are each faulty, or just incompatible in the 4x configuration with your motherboard.

[Halcyon]

I have never even heard of ZVVN. But no surprises for assuming that it's bargain basement rubbish.

Years ago I've just stopped buying anything made in China, which is difficult, but you can limit or eliminate your reliance on China if you're pedantic enough (which I am).

I mostly buy components manufactured in either the USA or Taiwan these days.

[SiliconWizard]

I hadn't either before, just looked up and these are on sale on Amazon, Aliexpress and the like.

One major point when selecting RAM is to at least chose ones for which the actual reference of the RAM chips is documented. Of course, if the brand of the RAM sticks is dubious, you still have no guarantee that the chips are genuine, but at lest that's a start. For ZVVN, I haven't seen a single reference for the chips they use. It's not a good sign.

[Haenk]

Over the years, we got a lot of modules with "odd" names. And I do think ZVVN rings a bell. It's been a few years, but we also had stuff like "AMORE", "AMZOR" and the like.
To my knowledge, these are all "UTT" (aka "untested") chips. Selling those was very common before DDR3 (mainly on DDR2 parts though), as there was a major lack of testing capacity.
Some companies made a good living using these very cheap chips - like MDT in Germany. They had their own testing equipment and therefor were able to only use known good parts and return the failed parts.