X86-Secret : ES Zone
PII Xeon 400 1M ES  (Week 20, Year 1998)   
Intel Confidential Q619ES / O82073BCA0-0091 / i'97 80523KX4001M

The Pentium II Xeon was basically a standard Pentium II with a bigger and greater L2 cache and the ability to work in quad CPU in SMP mode. The 400 MHz Pentium II Xeon was launched in late June '98 with caches sizes of 512 KB and 1 MB. This engineering sample features 1 MB of L2 cache and was produced in May '98. It comes in a SECC 2 cartridge like all other PII/PIII Xeon