if_rl.c より抜粋。

/*
* RealTek 8129/8139 PCI NIC driver
*
* Supports several extremely cheap PCI 10/100 adapters based on
* the RealTek chipset. Datasheets can be obtained from
* www.realtek.com.tw.
*
* Written by Bill Paul <[email protected]>
* Electrical Engineering Department
* Columbia University, New York City
*/

/*
* The RealTek 8139 PCI NIC redefines the meaning of 'low end.' This is
* probably the worst PCI ethernet controller ever made, with the possible
* exception of the FEAST chip made by SMC. The 8139 supports bus-master
* DMA, but it has a terrible interface that nullifies any performance
* gains that bus-master DMA usually offers.

以下略。


>>665
デスクトップ用ならすぐ上で出ているi82557 (Intel EtherExpress PRO/100 Model B)でしょう。
秋葉が遠い場合は別の手段を考えなければなりませんが。