It's been a while since we worked on a graphics card together, in part because this one took me almost a year to figure out, but I've finally got something resembling a complete story about it, so here we go.
On the bench we have an EVGA RTX 2080 XC, which is the same board design as the Founder's Edition, but with EVGA's heatsink design. The card came to me from another [H] member, who told the story that he had bought it new right after the 20 series was released, but that it had never delivered the same performance that most folks were seeing from their 2080s. Assuming that this had to do with thermal throttling, he had installed an aftermarket heatsink on it, which failed to improve its performance significantly. Eventually, he got tired of the much larger heatsink, and attempted to remove it, but in the process, tore one of the inductors apart, as we can see here.
After some discussion on the forum, he concluded repairing this was beyond his ability and sold the card to me. As an aside, I wish everyone selling used, disassembled graphics cards packed them as well as he did. He really did an excellent job.
Once the card arrived, the hunt for a replacement inductor began. I should note that it's possible that the card might have worked anyway, but the inductors are the only thing standing between the 12V input power coming out of the power stages and the load, which is the memory in this case. It's not a technically correct explanation, but you can imagine them as sort of a shock absorber. They take the big meaty pulses of 12V and smooth them out into a steadier flow of ~1.3V. That being the case, and this being a theoretically expensive card, I didn't feel it would be prudent to test the card before replacing the obviously damaged part.
Now, inductors are generally commodity items that can be sourced from almost any supplier in fairly standard ratings and sizes. At least, that's usually the case. In this case, though, we have a problem in that while the markings indicate that these inductors have a relatively common inductance rating of 0.47uH (that is, 470nH), they're an oddball physical size. In some cases, you could probably get away with just something close enough, but this card needs them to have an unusually low profile in order for the heatsink to fit. I took some measurements and came up with the following.
The thing that makes these really odd is that low Z-measurement. Most inductors you see on graphics cards are more like 4-5mm, but these are extra flat. A little extra digging reveals that this is an unusual, but apparently standard SMD size - 1284. The markings on them indicate the inductance, with the R indicating the decimal point, and the numbers theoretically being microhenries. So, this one 0.47uH. I'm not sure what the L is for. It could be a tolerance or temperature rating, or maybe a manufacturing date code. If anyone happens to know, please enlighten me.
I went off to DigiKey, and while I could find plenty of options in the right inductance and amperage specs from the usual suspects such as Murata, TDK and Kemet, none of them are flat enough to fit in this spot. I found the same thing at Mouser, and even on Ebay, I struck out. It was almost as if these things were made specifically for this card, which is hardly out of the question, given that this is an NVidia card. They LOVE to do stuff like that.
Eventually, it occurred to me that the manufacturing of this card probably happens entirely in Southeast Asia, so I checked Alibaba. You can buy literally anything from Alibaba. It took me a couple of hours of sifting through Alibaba storefronts, but eventually, I ran across a listing for products made by Sanhe Transformer, a smaller outfit in Tianjin that makes, among other things, inductors. As I looked through their various part numbers, I eventually concluded that this pretty much had to be the original source of the inductors on the card. The markings in the picture they had looked almost exactly the same as the original one, less the L.
The trouble was, Alibaba is a marketplace primarily intended for companies to sell stuff to each other, usually in large quantities. Notice that the minimum order quantity is 100 pieces. I tried everything I could think of, including just asking them, if there were a way I could order just a handful of samples, but they didn't seem to be set up to do that. So, after a few emails back and forth with a very nice lady named Echo...
And a couple of weeks waiting on the mail...
I had a spool of 100 shiny new SMD 1284 package 0.47uH inductors on my workbench.
On the bench we have an EVGA RTX 2080 XC, which is the same board design as the Founder's Edition, but with EVGA's heatsink design. The card came to me from another [H] member, who told the story that he had bought it new right after the 20 series was released, but that it had never delivered the same performance that most folks were seeing from their 2080s. Assuming that this had to do with thermal throttling, he had installed an aftermarket heatsink on it, which failed to improve its performance significantly. Eventually, he got tired of the much larger heatsink, and attempted to remove it, but in the process, tore one of the inductors apart, as we can see here.
After some discussion on the forum, he concluded repairing this was beyond his ability and sold the card to me. As an aside, I wish everyone selling used, disassembled graphics cards packed them as well as he did. He really did an excellent job.
Once the card arrived, the hunt for a replacement inductor began. I should note that it's possible that the card might have worked anyway, but the inductors are the only thing standing between the 12V input power coming out of the power stages and the load, which is the memory in this case. It's not a technically correct explanation, but you can imagine them as sort of a shock absorber. They take the big meaty pulses of 12V and smooth them out into a steadier flow of ~1.3V. That being the case, and this being a theoretically expensive card, I didn't feel it would be prudent to test the card before replacing the obviously damaged part.
Now, inductors are generally commodity items that can be sourced from almost any supplier in fairly standard ratings and sizes. At least, that's usually the case. In this case, though, we have a problem in that while the markings indicate that these inductors have a relatively common inductance rating of 0.47uH (that is, 470nH), they're an oddball physical size. In some cases, you could probably get away with just something close enough, but this card needs them to have an unusually low profile in order for the heatsink to fit. I took some measurements and came up with the following.
The thing that makes these really odd is that low Z-measurement. Most inductors you see on graphics cards are more like 4-5mm, but these are extra flat. A little extra digging reveals that this is an unusual, but apparently standard SMD size - 1284. The markings on them indicate the inductance, with the R indicating the decimal point, and the numbers theoretically being microhenries. So, this one 0.47uH. I'm not sure what the L is for. It could be a tolerance or temperature rating, or maybe a manufacturing date code. If anyone happens to know, please enlighten me.
I went off to DigiKey, and while I could find plenty of options in the right inductance and amperage specs from the usual suspects such as Murata, TDK and Kemet, none of them are flat enough to fit in this spot. I found the same thing at Mouser, and even on Ebay, I struck out. It was almost as if these things were made specifically for this card, which is hardly out of the question, given that this is an NVidia card. They LOVE to do stuff like that.
Eventually, it occurred to me that the manufacturing of this card probably happens entirely in Southeast Asia, so I checked Alibaba. You can buy literally anything from Alibaba. It took me a couple of hours of sifting through Alibaba storefronts, but eventually, I ran across a listing for products made by Sanhe Transformer, a smaller outfit in Tianjin that makes, among other things, inductors. As I looked through their various part numbers, I eventually concluded that this pretty much had to be the original source of the inductors on the card. The markings in the picture they had looked almost exactly the same as the original one, less the L.
The trouble was, Alibaba is a marketplace primarily intended for companies to sell stuff to each other, usually in large quantities. Notice that the minimum order quantity is 100 pieces. I tried everything I could think of, including just asking them, if there were a way I could order just a handful of samples, but they didn't seem to be set up to do that. So, after a few emails back and forth with a very nice lady named Echo...
And a couple of weeks waiting on the mail...
I had a spool of 100 shiny new SMD 1284 package 0.47uH inductors on my workbench.