My AMD DX4 change its cpuid when used in WB/WT mode so I'm not sure ... I guess your mobo supports wb chips, right ?

Deksor wrote:

I guess your mobo supports wb chips, right ?

Yes. All the benchmarks above were done on the same modern-ish motherboard (4SA W2/W5 - vlb/isa/pci combo), which supports WB, and had the motherboard jumper settings configured for P24D but at 3.45V.

The real &EW chip provides a cpuid of 0490h (16kB L1 WB), and the benchmark shows a 20% boost. All other non-WB chips, as well as the fake WB chips show 0480h (16kB L1 WT).

Well, what's more interesting is that it's called "A80486DX4WB100". I've never seen an &EW with "WB" in the name.

Rechecked the processors I have - as already stated, there's no explicit WB tag on them.
Some crafty scammers at work.

Let's call that the PCChips DX4, with its faked cache x)

About the font on the fake chip from gloomkeep: The apostrophe before the years 89 and 94 is lower then normal.

My DX4 &EW chip has CPUID 0483h, in WT mode.

gerwin wrote:

My DX4 &EW chip has CPUID 0483h, in WT mode.

Ahh so that's the difference, great!

Here are the two fakes, alongside a genuine &EW and &E.

gloomkeep wrote:

Greetings. It appears that two Intel DX4-100 writeback CPUs (&EW tag) I acquired from one source might be fake. Fake in that the […]
Show full quote

Greetings. It appears that two Intel DX4-100 writeback CPUs (&EW tag) I acquired from one source might be fake. Fake in that the L1 cache won't work in WB mode.

The performance and cpuid is identical to a standard non-WB DX4-100 (&E and Overdrive), so I guess someone went to the effort of re-engraving an &E? The engraved font looks weird, and the Intel logo looks splotchy (you need to zoom in to see).

I've included some doom benchmark results below, against other CPUs I tested at the same time - including a real &EW WB chip (which quotes the correct cpuid of 0490h, and has white text rather than engraving on the chip). Does anyone know if fakes are common?

# DOOM 1.9s TICKS, CPU
1842, &EW (confirmed real, acquired from a different source)
2206, &E
2207, &E
2207, ODP100
2207, &EW (fake #1)
2208, &EW (fake #2)
2208, ODPR100

It's already been mentioned, but it's a faaaaaake 🤣

The font is off, that should already be a dead giveaway. But at least your chip works.

I used to research the counterfeits and read a lot about it years ago. Most sources I read back then no longer exist, alas.

But anyway, if ever in doubt about something like the font of chips like these, I could advice to ask on CPU world. If anyone can spot a fake print on a CPU, it's gonna be on that forum I reckon.