Link Capacity Test Variances

Hi All-
I’m curious why I see some fairly wide variations in link capacity tests. The results from 2 SM’s on the same 900 MHz AP are below. As you can see, one has an aggregate of about 3.5 Mbits, while the other is about 2.3 Mbits

Stats for LUID: 4 Test Duration: 10 Pkt Length: 1522

Downlink RATE: 2446540 bps
Uplink RATE: 1094860 bps
Aggregate RATE: 3541400 bps
Pkt Xmt (Act/Exp): 891/0
Pkt Rcv (Act/Exp): 1983/0

Downlink Efficiency: 87 Percent
Downlink Index (Act/Max): 87/100
Frag Count (Act/Exp): 54737/47784

Uplink Efficiency: 93 Percent
Uplink Index (Act/Max): 93/100
Frag Count (Act/Exp): 22840/21384

Stats for LUID: 6 Test Duration: 10 Pkt Length: 1522

Downlink RATE: 1393459 bps
Uplink RATE: 974438 bps
Aggregate RATE: 2367897 bps
Pkt Xmt (Act/Exp): 793/0
Pkt Rcv (Act/Exp): 1126/0

Downlink Efficiency: 86 Percent
Downlink Index (Act/Max): 86/100
Frag Count (Act/Exp): 31383/27216

Uplink Efficiency: 91 Percent
Uplink Index (Act/Max): 91/100
Frag Count (Act/Exp): 20857/19032
On the other hand, a 2nd 900 MHz AP has lower overall throughput and smaller variations. Here’s a sample:

Stats for LUID: 2 Test Duration: 10 Pkt Length: 1522

Downlink RATE: 1454336 bps
Uplink RATE: 460800 bps
Aggregate RATE: 1915136 bps
Pkt Xmt (Act/Exp): 375/0
Pkt Rcv (Act/Exp): 1178/0

Downlink Efficiency: 100 Percent
Downlink Index (Act/Max): 100/100
Frag Count (Act/Exp): 28405/28405

Uplink Efficiency: 75 Percent
Uplink Index (Act/Max): 75/100
Frag Count (Act/Exp): 11958/9000

Anybody have any thoughts on the variations and why the 2nd AP has lower throughput?